/reads kandel
@neurocat.bsky.social
software engineer learns neuroscience.
currently reading a chapter of kandel 6e a day and posting through it.
main: https://bsky.app/profile/emmz.bsky.social
currently reading a chapter of kandel 6e a day and posting through it.
main: https://bsky.app/profile/emmz.bsky.social
64. the aging brain
over time, as healthcare and nutrition improve, humans live longer: average life span in the US was only ~50 in 1900, and is ~80 now.
sadly, this means more of us are encountering the cognitive impairments that come with age, including alzheimer's and other dementias.
over time, as healthcare and nutrition improve, humans live longer: average life span in the US was only ~50 in 1900, and is ~80 now.
sadly, this means more of us are encountering the cognitive impairments that come with age, including alzheimer's and other dementias.
March 15, 2025 at 7:36 AM
64. the aging brain
over time, as healthcare and nutrition improve, humans live longer: average life span in the US was only ~50 in 1900, and is ~80 now.
sadly, this means more of us are encountering the cognitive impairments that come with age, including alzheimer's and other dementias.
over time, as healthcare and nutrition improve, humans live longer: average life span in the US was only ~50 in 1900, and is ~80 now.
sadly, this means more of us are encountering the cognitive impairments that come with age, including alzheimer's and other dementias.
63. genetic mechanisms in neurodegenerative diseases of the nervous system
the late-onset degenerative diseases fall into 2 categories:
- sporadic, i.e. unknown etiology (majority of alzheimer's and parkinson's cases)
- inherited (huntington's, spinocerebellar ataxia, several muscular atrophies)
the late-onset degenerative diseases fall into 2 categories:
- sporadic, i.e. unknown etiology (majority of alzheimer's and parkinson's cases)
- inherited (huntington's, spinocerebellar ataxia, several muscular atrophies)
March 14, 2025 at 8:28 AM
63. genetic mechanisms in neurodegenerative diseases of the nervous system
the late-onset degenerative diseases fall into 2 categories:
- sporadic, i.e. unknown etiology (majority of alzheimer's and parkinson's cases)
- inherited (huntington's, spinocerebellar ataxia, several muscular atrophies)
the late-onset degenerative diseases fall into 2 categories:
- sporadic, i.e. unknown etiology (majority of alzheimer's and parkinson's cases)
- inherited (huntington's, spinocerebellar ataxia, several muscular atrophies)
62. disorders affecting social cognition: autism spectrum disorder
neurodevelopmental disorders can affect perception, general cognition, or, as in autism, social cognition.
autism has 2 defining features:
- impaired social communication
- stereotyped behaviors with highly restricted interests
neurodevelopmental disorders can affect perception, general cognition, or, as in autism, social cognition.
autism has 2 defining features:
- impaired social communication
- stereotyped behaviors with highly restricted interests
March 13, 2025 at 7:38 AM
62. disorders affecting social cognition: autism spectrum disorder
neurodevelopmental disorders can affect perception, general cognition, or, as in autism, social cognition.
autism has 2 defining features:
- impaired social communication
- stereotyped behaviors with highly restricted interests
neurodevelopmental disorders can affect perception, general cognition, or, as in autism, social cognition.
autism has 2 defining features:
- impaired social communication
- stereotyped behaviors with highly restricted interests
61. disorders of mood and anxiety
some stats:
- 19% of people have major depression at some point in their lives, 8.3% each year
- bipolar disorder (depression plus at least one episode of mania) affects ~1% of people
- 28.5% of people have an anxiety disorder at some point in their lives
some stats:
- 19% of people have major depression at some point in their lives, 8.3% each year
- bipolar disorder (depression plus at least one episode of mania) affects ~1% of people
- 28.5% of people have an anxiety disorder at some point in their lives
March 12, 2025 at 8:09 AM
61. disorders of mood and anxiety
some stats:
- 19% of people have major depression at some point in their lives, 8.3% each year
- bipolar disorder (depression plus at least one episode of mania) affects ~1% of people
- 28.5% of people have an anxiety disorder at some point in their lives
some stats:
- 19% of people have major depression at some point in their lives, 8.3% each year
- bipolar disorder (depression plus at least one episode of mania) affects ~1% of people
- 28.5% of people have an anxiety disorder at some point in their lives
60. disorders of thought and volition in schizophrenia
schizophrenia symptoms fall in 3 clusters:
- cognitive (impairment of executive function, memory, fluency, and emotional processing)
- deficit (loss of motivation, poverty of thought)
- psychotic (hallucinations, delusions, disordered thought)
schizophrenia symptoms fall in 3 clusters:
- cognitive (impairment of executive function, memory, fluency, and emotional processing)
- deficit (loss of motivation, poverty of thought)
- psychotic (hallucinations, delusions, disordered thought)
March 11, 2025 at 5:40 AM
60. disorders of thought and volition in schizophrenia
schizophrenia symptoms fall in 3 clusters:
- cognitive (impairment of executive function, memory, fluency, and emotional processing)
- deficit (loss of motivation, poverty of thought)
- psychotic (hallucinations, delusions, disordered thought)
schizophrenia symptoms fall in 3 clusters:
- cognitive (impairment of executive function, memory, fluency, and emotional processing)
- deficit (loss of motivation, poverty of thought)
- psychotic (hallucinations, delusions, disordered thought)
59. disorders of conscious and unconscious mental processes
depending on context, "cognition" can either mean "all information processing in the brain" or "higher-level processes that underlie conscious experience".
cognitive therapy, which operates on thoughts, aligns more with the latter.
depending on context, "cognition" can either mean "all information processing in the brain" or "higher-level processes that underlie conscious experience".
cognitive therapy, which operates on thoughts, aligns more with the latter.
March 10, 2025 at 7:23 AM
59. disorders of conscious and unconscious mental processes
depending on context, "cognition" can either mean "all information processing in the brain" or "higher-level processes that underlie conscious experience".
cognitive therapy, which operates on thoughts, aligns more with the latter.
depending on context, "cognition" can either mean "all information processing in the brain" or "higher-level processes that underlie conscious experience".
cognitive therapy, which operates on thoughts, aligns more with the latter.
58. seizures and epilepsy
we can't carry out invasive experimental studies in human brains, so a lot of what we know was learned from stroke or injury–trying to tell from functional deficits what a missing brain area did.
seizures provide similar data, but for when a brain area is hyperactive.
we can't carry out invasive experimental studies in human brains, so a lot of what we know was learned from stroke or injury–trying to tell from functional deficits what a missing brain area did.
seizures provide similar data, but for when a brain area is hyperactive.
March 9, 2025 at 8:07 AM
58. seizures and epilepsy
we can't carry out invasive experimental studies in human brains, so a lot of what we know was learned from stroke or injury–trying to tell from functional deficits what a missing brain area did.
seizures provide similar data, but for when a brain area is hyperactive.
we can't carry out invasive experimental studies in human brains, so a lot of what we know was learned from stroke or injury–trying to tell from functional deficits what a missing brain area did.
seizures provide similar data, but for when a brain area is hyperactive.
57. diseases of the peripheral nerve and motor unit
motor unit disorders are categorized by part affected:
- motor neuron cell body (motor neuron diseases)
- motor neuron axon (peripheral neuropathies)
- neuromuscular junction (disorders of the neuromuscular junction)
- muscle fibers (myopathies)
motor unit disorders are categorized by part affected:
- motor neuron cell body (motor neuron diseases)
- motor neuron axon (peripheral neuropathies)
- neuromuscular junction (disorders of the neuromuscular junction)
- muscle fibers (myopathies)
March 8, 2025 at 10:51 AM
57. diseases of the peripheral nerve and motor unit
motor unit disorders are categorized by part affected:
- motor neuron cell body (motor neuron diseases)
- motor neuron axon (peripheral neuropathies)
- neuromuscular junction (disorders of the neuromuscular junction)
- muscle fibers (myopathies)
motor unit disorders are categorized by part affected:
- motor neuron cell body (motor neuron diseases)
- motor neuron axon (peripheral neuropathies)
- neuromuscular junction (disorders of the neuromuscular junction)
- muscle fibers (myopathies)
56. decision-making and consciousness
we consider a behavior "cognitive" if it exhibits:
- contingency (inputs do not necessitate particular outcomes)
- freedom from immediacy (there's some kind of time course)
decisions, defined here as provisional commitments to action, are cognitive.
we consider a behavior "cognitive" if it exhibits:
- contingency (inputs do not necessitate particular outcomes)
- freedom from immediacy (there's some kind of time course)
decisions, defined here as provisional commitments to action, are cognitive.
March 7, 2025 at 9:53 AM
56. decision-making and consciousness
we consider a behavior "cognitive" if it exhibits:
- contingency (inputs do not necessitate particular outcomes)
- freedom from immediacy (there's some kind of time course)
decisions, defined here as provisional commitments to action, are cognitive.
we consider a behavior "cognitive" if it exhibits:
- contingency (inputs do not necessitate particular outcomes)
- freedom from immediacy (there's some kind of time course)
decisions, defined here as provisional commitments to action, are cognitive.
55. language
animals communicate, but none come close to what we do with language: provide information, express emotion, comment on past and future, tell stories, and more, all by age 3!
"phonemes" are basic units of sound ("c" in "cat"). "morphemes" are basic units of meaning ("un" in "undo").
animals communicate, but none come close to what we do with language: provide information, express emotion, comment on past and future, tell stories, and more, all by age 3!
"phonemes" are basic units of sound ("c" in "cat"). "morphemes" are basic units of meaning ("un" in "undo").
March 6, 2025 at 9:13 AM
55. language
animals communicate, but none come close to what we do with language: provide information, express emotion, comment on past and future, tell stories, and more, all by age 3!
"phonemes" are basic units of sound ("c" in "cat"). "morphemes" are basic units of meaning ("un" in "undo").
animals communicate, but none come close to what we do with language: provide information, express emotion, comment on past and future, tell stories, and more, all by age 3!
"phonemes" are basic units of sound ("c" in "cat"). "morphemes" are basic units of meaning ("un" in "undo").
54. the hippocampus and the neural basis of explicit memory storage
working memory relies on ongoing activity in PFC–distractions are destructive.
long-term explicit memory is implemented as changes to synaptic structure in cortex. hippocampus is needed, but how exactly that loop works is unclear.
working memory relies on ongoing activity in PFC–distractions are destructive.
long-term explicit memory is implemented as changes to synaptic structure in cortex. hippocampus is needed, but how exactly that loop works is unclear.
March 5, 2025 at 11:09 AM
54. the hippocampus and the neural basis of explicit memory storage
working memory relies on ongoing activity in PFC–distractions are destructive.
long-term explicit memory is implemented as changes to synaptic structure in cortex. hippocampus is needed, but how exactly that loop works is unclear.
working memory relies on ongoing activity in PFC–distractions are destructive.
long-term explicit memory is implemented as changes to synaptic structure in cortex. hippocampus is needed, but how exactly that loop works is unclear.
53. cellular mechanisms of implicit memory storage and the biological basis of Individuality
long-term implicit memory storage happens in:
- neocortex (priming)
- striatum (skills, habits)
- amygdala (threat conditioning)
- cerebellum (motor skills)
- reflex pathways (habituation, sensitization)
long-term implicit memory storage happens in:
- neocortex (priming)
- striatum (skills, habits)
- amygdala (threat conditioning)
- cerebellum (motor skills)
- reflex pathways (habituation, sensitization)
March 4, 2025 at 7:55 AM
53. cellular mechanisms of implicit memory storage and the biological basis of Individuality
long-term implicit memory storage happens in:
- neocortex (priming)
- striatum (skills, habits)
- amygdala (threat conditioning)
- cerebellum (motor skills)
- reflex pathways (habituation, sensitization)
long-term implicit memory storage happens in:
- neocortex (priming)
- striatum (skills, habits)
- amygdala (threat conditioning)
- cerebellum (motor skills)
- reflex pathways (habituation, sensitization)
52. learning and memory
learning is a change in behavior from acquiring knowledge. memory is processes by which knowledge is encoded, stored, and retrieved.
there are different kinds of memory, classified by time course and information type. memory errors give us clues about how the system works.
learning is a change in behavior from acquiring knowledge. memory is processes by which knowledge is encoded, stored, and retrieved.
there are different kinds of memory, classified by time course and information type. memory errors give us clues about how the system works.
March 3, 2025 at 10:24 AM
52. learning and memory
learning is a change in behavior from acquiring knowledge. memory is processes by which knowledge is encoded, stored, and retrieved.
there are different kinds of memory, classified by time course and information type. memory errors give us clues about how the system works.
learning is a change in behavior from acquiring knowledge. memory is processes by which knowledge is encoded, stored, and retrieved.
there are different kinds of memory, classified by time course and information type. memory errors give us clues about how the system works.
51. sexual differentiation of the nervous system
humans have 23 chromosomal pairs.
22 of these ("autosomes") are the same between the sexes, while the 23rd pair ("sex chromosomes") differs: XX for females, XY for males.
XX → female and XY → male genotypes are conserved across most mammals.
humans have 23 chromosomal pairs.
22 of these ("autosomes") are the same between the sexes, while the 23rd pair ("sex chromosomes") differs: XX for females, XY for males.
XX → female and XY → male genotypes are conserved across most mammals.
March 2, 2025 at 10:36 AM
51. sexual differentiation of the nervous system
humans have 23 chromosomal pairs.
22 of these ("autosomes") are the same between the sexes, while the 23rd pair ("sex chromosomes") differs: XX for females, XY for males.
XX → female and XY → male genotypes are conserved across most mammals.
humans have 23 chromosomal pairs.
22 of these ("autosomes") are the same between the sexes, while the 23rd pair ("sex chromosomes") differs: XX for females, XY for males.
XX → female and XY → male genotypes are conserved across most mammals.
50. repairing the damaged brain
developmental neuroscience has recently suggested new approaches to 2 clinical applications we thought were impossible:
- regrowth of axons and reformation of synapses in CNS after injury
- regeneration of neurons after they're killed by damage or disease
developmental neuroscience has recently suggested new approaches to 2 clinical applications we thought were impossible:
- regrowth of axons and reformation of synapses in CNS after injury
- regeneration of neurons after they're killed by damage or disease
March 1, 2025 at 9:16 AM
50. repairing the damaged brain
developmental neuroscience has recently suggested new approaches to 2 clinical applications we thought were impossible:
- regrowth of axons and reformation of synapses in CNS after injury
- regeneration of neurons after they're killed by damage or disease
developmental neuroscience has recently suggested new approaches to 2 clinical applications we thought were impossible:
- regrowth of axons and reformation of synapses in CNS after injury
- regeneration of neurons after they're killed by damage or disease
49. experience and the refinement of synaptic connections
neural circuitry in mammals is first roughly formed by genetics, then refined by experience. the second stage in humans is extra long.
this means we're pretty helpless at birth, but our brains are custom-fit to our bodies and environment.
neural circuitry in mammals is first roughly formed by genetics, then refined by experience. the second stage in humans is extra long.
this means we're pretty helpless at birth, but our brains are custom-fit to our bodies and environment.
February 28, 2025 at 9:25 AM
49. experience and the refinement of synaptic connections
neural circuitry in mammals is first roughly formed by genetics, then refined by experience. the second stage in humans is extra long.
this means we're pretty helpless at birth, but our brains are custom-fit to our bodies and environment.
neural circuitry in mammals is first roughly formed by genetics, then refined by experience. the second stage in humans is extra long.
this means we're pretty helpless at birth, but our brains are custom-fit to our bodies and environment.
48. formation and elimination of synapses
when axons get to where they're going, they form synapses. this is the last step before the brain can start to process information!
3 parts to synapse formation:
- initial partnering
- growing pre- and postsynaptic sites
- maturation and rearrangement
when axons get to where they're going, they form synapses. this is the last step before the brain can start to process information!
3 parts to synapse formation:
- initial partnering
- growing pre- and postsynaptic sites
- maturation and rearrangement
February 27, 2025 at 9:55 AM
48. formation and elimination of synapses
when axons get to where they're going, they form synapses. this is the last step before the brain can start to process information!
3 parts to synapse formation:
- initial partnering
- growing pre- and postsynaptic sites
- maturation and rearrangement
when axons get to where they're going, they form synapses. this is the last step before the brain can start to process information!
3 parts to synapse formation:
- initial partnering
- growing pre- and postsynaptic sites
- maturation and rearrangement
47. the growth and guidance of axons
neurons are born, migrate to their homes, ~then grow axons and dendrites to connect up with each other!
some axons are extremely long, and they have to grow in the right direction past a bunch of distractors before reaching their correct synaptic targets.
neurons are born, migrate to their homes, ~then grow axons and dendrites to connect up with each other!
some axons are extremely long, and they have to grow in the right direction past a bunch of distractors before reaching their correct synaptic targets.
February 26, 2025 at 8:27 AM
47. the growth and guidance of axons
neurons are born, migrate to their homes, ~then grow axons and dendrites to connect up with each other!
some axons are extremely long, and they have to grow in the right direction past a bunch of distractors before reaching their correct synaptic targets.
neurons are born, migrate to their homes, ~then grow axons and dendrites to connect up with each other!
some axons are extremely long, and they have to grow in the right direction past a bunch of distractors before reaching their correct synaptic targets.
46. differentiation and survival of nerve cells
in the neural tube, ectoderm cells first become CNS stem cells ("neuroepithelial cells"), then progenitor cells ("radial glial cells"). these have their cell bodies near the tube's hollow ventricle, and long fibers extending towards the pial surface.
in the neural tube, ectoderm cells first become CNS stem cells ("neuroepithelial cells"), then progenitor cells ("radial glial cells"). these have their cell bodies near the tube's hollow ventricle, and long fibers extending towards the pial surface.
February 25, 2025 at 8:38 AM
46. differentiation and survival of nerve cells
in the neural tube, ectoderm cells first become CNS stem cells ("neuroepithelial cells"), then progenitor cells ("radial glial cells"). these have their cell bodies near the tube's hollow ventricle, and long fibers extending towards the pial surface.
in the neural tube, ectoderm cells first become CNS stem cells ("neuroepithelial cells"), then progenitor cells ("radial glial cells"). these have their cell bodies near the tube's hollow ventricle, and long fibers extending towards the pial surface.
45. patterning the nervous system
neural development falls into 3 epochs:
- generation and differentiation of neurons and glia
- genetically-guided migration and wiring up
- experience-guided refinement of circuits
this chapter is about the epoch 1 and the >1000 cell types in the mammalian brain.
neural development falls into 3 epochs:
- generation and differentiation of neurons and glia
- genetically-guided migration and wiring up
- experience-guided refinement of circuits
this chapter is about the epoch 1 and the >1000 cell types in the mammalian brain.
February 24, 2025 at 9:34 AM
45. patterning the nervous system
neural development falls into 3 epochs:
- generation and differentiation of neurons and glia
- genetically-guided migration and wiring up
- experience-guided refinement of circuits
this chapter is about the epoch 1 and the >1000 cell types in the mammalian brain.
neural development falls into 3 epochs:
- generation and differentiation of neurons and glia
- genetically-guided migration and wiring up
- experience-guided refinement of circuits
this chapter is about the epoch 1 and the >1000 cell types in the mammalian brain.
44. sleep and wakefulness
a "polysomnogram" is used to measure a night of sleep. it is built out of:
- electroencephalogram (EEG) for brain activity
- electro-oculogram (EOG) for eye movement
- electromyogram (EMG) for muscle tone
in sleep disorder studies, respiration will often be tracked too.
a "polysomnogram" is used to measure a night of sleep. it is built out of:
- electroencephalogram (EEG) for brain activity
- electro-oculogram (EOG) for eye movement
- electromyogram (EMG) for muscle tone
in sleep disorder studies, respiration will often be tracked too.
February 23, 2025 at 8:17 AM
44. sleep and wakefulness
a "polysomnogram" is used to measure a night of sleep. it is built out of:
- electroencephalogram (EEG) for brain activity
- electro-oculogram (EOG) for eye movement
- electromyogram (EMG) for muscle tone
in sleep disorder studies, respiration will often be tracked too.
a "polysomnogram" is used to measure a night of sleep. it is built out of:
- electroencephalogram (EEG) for brain activity
- electro-oculogram (EOG) for eye movement
- electromyogram (EMG) for muscle tone
in sleep disorder studies, respiration will often be tracked too.
43. motivation, reward, and addictive states
sometimes we (and animals!) see a snack and really want to eat it. other times we don't care. the stimulus is the same, so the difference is in motivation.
motivation is influenced by both internal (physiological and cognitive) and external variables.
sometimes we (and animals!) see a snack and really want to eat it. other times we don't care. the stimulus is the same, so the difference is in motivation.
motivation is influenced by both internal (physiological and cognitive) and external variables.
February 22, 2025 at 8:59 AM
43. motivation, reward, and addictive states
sometimes we (and animals!) see a snack and really want to eat it. other times we don't care. the stimulus is the same, so the difference is in motivation.
motivation is influenced by both internal (physiological and cognitive) and external variables.
sometimes we (and animals!) see a snack and really want to eat it. other times we don't care. the stimulus is the same, so the difference is in motivation.
motivation is influenced by both internal (physiological and cognitive) and external variables.
42. emotion
emotion is complicated to define or organize, but we can talk about its valence (pleasantness) and intensity (arousal level).
emotions correlate with physiological responses, but we don't know which way the causation goes there.
humans are uniquely able to describe their emotions.
emotion is complicated to define or organize, but we can talk about its valence (pleasantness) and intensity (arousal level).
emotions correlate with physiological responses, but we don't know which way the causation goes there.
humans are uniquely able to describe their emotions.
February 21, 2025 at 9:03 AM
42. emotion
emotion is complicated to define or organize, but we can talk about its valence (pleasantness) and intensity (arousal level).
emotions correlate with physiological responses, but we don't know which way the causation goes there.
humans are uniquely able to describe their emotions.
emotion is complicated to define or organize, but we can talk about its valence (pleasantness) and intensity (arousal level).
emotions correlate with physiological responses, but we don't know which way the causation goes there.
humans are uniquely able to describe their emotions.
41. the hypothalamus: autonomic, hormonal, and behavioral control of survival
the hypothalamus acts on 3 systems:
- the autonomic nervous system, to regulate unconscious functions like heart rate
- the neuroendocrine system, to release hormones
- neural pathways that mediate motivated behavior
the hypothalamus acts on 3 systems:
- the autonomic nervous system, to regulate unconscious functions like heart rate
- the neuroendocrine system, to release hormones
- neural pathways that mediate motivated behavior
February 20, 2025 at 9:08 AM
41. the hypothalamus: autonomic, hormonal, and behavioral control of survival
the hypothalamus acts on 3 systems:
- the autonomic nervous system, to regulate unconscious functions like heart rate
- the neuroendocrine system, to release hormones
- neural pathways that mediate motivated behavior
the hypothalamus acts on 3 systems:
- the autonomic nervous system, to regulate unconscious functions like heart rate
- the neuroendocrine system, to release hormones
- neural pathways that mediate motivated behavior
40. the brain stem
brains of primitive vertebrates (reptiles, amphibians, fish) have tiny forebrains, mostly for olfaction, but they still move, eat, sleep, reproduce, and react to emergencies.
physically and functionally, the brain stem exists between the spinal cord and the rest of the brain.
brains of primitive vertebrates (reptiles, amphibians, fish) have tiny forebrains, mostly for olfaction, but they still move, eat, sleep, reproduce, and react to emergencies.
physically and functionally, the brain stem exists between the spinal cord and the rest of the brain.
February 19, 2025 at 10:36 AM
40. the brain stem
brains of primitive vertebrates (reptiles, amphibians, fish) have tiny forebrains, mostly for olfaction, but they still move, eat, sleep, reproduce, and react to emergencies.
physically and functionally, the brain stem exists between the spinal cord and the rest of the brain.
brains of primitive vertebrates (reptiles, amphibians, fish) have tiny forebrains, mostly for olfaction, but they still move, eat, sleep, reproduce, and react to emergencies.
physically and functionally, the brain stem exists between the spinal cord and the rest of the brain.