Neurophysiology 1

The cerebral cortex and intellectual functions of the brain

Physiologic anatomy of the cerebral cortex

cell types

granular layer cells: small pyramidal cells, spiny stellate interneurons

fusiform layer: pyramidal cells, fusiform cells

pyramidal cells

GABA-interneurons: smooth stellate cells, basket cels, chandelier cells, double bouquet cells

cortical layers

I	molecular layer
II	external granular layer
III	(external) pyramidal cell layer
IV	internal granular layer
V	(internal) large pyramidal cell layer
VI	multiform (fusiform cell) layer

agranular cortex... motor

granular cortex... sensory

thalamocortical system

powerpoint view of cortical functioning

The Cortex

archicortex

hippocampus

olfactory cortex

neocortex

connections of the neocortex

gating through the thalamus

midbrain & neocortex to pulvinar to neocortex

eye to lateral geniculate body to primary visual cortex

auditory fibers to medial geniculate body to primary auditory cortex

ventral nucleus

body to somatosensory cortex

cerebellum to motor cortex

basal ganglia to premotor cortex

lateral nucleus to and from posterior parietal cortex

mammillary body of hypothalamus to anterior nucleus to cingulate gyrus

damage to mammillary bodies can result in anterograde amnesia

amygdaloid nucleus, hypothalamus, & olfactory area to mediodorsal nucleus to frontal cortical lobes

raphe nucleus, locus coeruleus, & basal nuclei to intralaminar thalamic nucleus diffusely to cortex

cortex to basal nuclei (striatum) to thalamus to frontal motor cortex

Cortical functional areas

primary sensory areas

somatic, visual, auditory

examples of loss: anencephalic infant

sensory association areas

examples of loss: dyslexia

Wernicke’s area

role in cerebration

storage of complicated memory patterns?

angular gyrus for visual signals

dominant hemisphere

role of language in function of Wernicke’s area

Wernicke’s area in the nondominant hemisphere

visual patterning, spatial relationships, somatic experiencing

face recognition area

inferior occipital and temporal lobes

prosopagnosia (prosophenosia)

prefrontal areas

choice of behavioral options for social/physical situations

prevention of distractibility [loss of thought sequencing]

elaboration of thought and prognostication

The limbic system as the center of emotions

this material has been removed to a separate lecture outline on the limbic system

Thoughts, consciousness, and memory

holistic theory of thoughts

cortical, thalamic, limbic, and upper reticular involvement in analysis of general qualities

cerebral cortex in formation of discrete qualities

consciousness... continuing stream of awareness of surroundings/thoughts

memory

sensory memory

very short, hundreds of msec

primary memory

a few seconds to a few minutes

replaced by new data

secondary memory

long-term storage

requires search

physiological basis of memory ¹

reverberating circuit theory of primary memory

alteration of synapses for secondary memory

anatomic changes in synapses

physicochemical changes in pre- or postsynaptic elements

habituation and facilitator terminals

serotonin

adenylate cyclase

cyclic AMP [cAMP]

protein kinase

reduction of potassium conductance

prolongation of action potential

prolongation of calcium channel activation

increased release of neurotransmitter

formation of the memory engram

consolidation of memory

5–10 min for minimal, one hour for maximal

role of rehearsal in memory transference

codification of memories during consolidation

role of the hippocampi (most medial portions of temporal lobe cortex)

anterograde amnesia

role of thalamus?

retrograde amnesia

Analytical operations of the brain

analysis of information by splitting its qualities

analysis of new information by comparison with memories

analysis of patterns

Function of the brain in communication

sensory aspects

auditory receptive aphasia [word deafness]

visual receptive aphasia [word blindness]

Wernicke’s aphasia [sensory aphasia]

inability to interpret thought

motor aspects

formation of thoughts to be expressed

Wernicke’s area

motor control of vocalization

Broca’s area

motor aphasia

articulation

facial and laryngeal regions of motor cortex

cerebellum, basal ganglia, sensory cortex

Go to beginning