Neurosciences 27+30+31
HC 4
Chapter 27
The cortical layers include the following:
I. Molecular layer, consisting of a dense network of interwoven nerve fibers that
receives input from modulatory dendrites.
II. External granular layer, integrates information within the cortex
III. External pyramidal layer, contains pyramidal neurons so many cortico-cortical
projections.
IV. Internal granular layer, receives input from the thalamus as it consists of stellate
neurons.
V. Internal pyramidal layer, output to spinal cord, brainstem and striatum.
VI. Multiform layer, output to thalamus.
The layers histologically, in terms of cell density and in size may differ depending on the
cortex; the motor cortex has a specialized V layer, the sensory cortex and special IV layer
and the associative cortex more a distinct III layer. So, there are different cytoarchitectural
areas related to function. The cortical layers themselves are arranged in columns, so they
have both horizontal and vertical connecting features.
Within the cerebral cortex, there are also connections between the hemispheres, known as
commissural connections. Actually, any left-right structure is connected by commissural
fibers. Different cortical areas within a hemisphere have associative connections, the
cortico-cortical connections.
The association cortices have three main functions:
- Parallel processing of sensory information to unimodal association areas
- Unimodal sensory inputs converge to multimodal association
- Posterior parietal association areas are interconnected with frontal association
areas, which thus help to guide behavior.
The different association cortices:
- Parietal: atrophy leads to the inability to attend to objects or one’s own body in a
portion of space despite the fact that visual, motor and sensory activity remains
intact. So, deficits in attention, perception of motion, special localization.
- Temporal: atrophy leads to the inability to recognize and identify colors, faces,
objects, etc.
- Frontal: atrophy has various serious and devastating effects associated with the
functioning of the frontal cortex in:
o Restraint: impaired judgement, concentration, no restraint on socially
inappropriate responses
o Initiative: impaired curiosity, spontaneity, motivation, creativity.
o Order: impaired abstract reasoning, planning, organization, perspective
taking.
Chapter 30
Humans have two qualitatively different ways of storing memory, namely via:
HC 4
Chapter 27
The cortical layers include the following:
I. Molecular layer, consisting of a dense network of interwoven nerve fibers that
receives input from modulatory dendrites.
II. External granular layer, integrates information within the cortex
III. External pyramidal layer, contains pyramidal neurons so many cortico-cortical
projections.
IV. Internal granular layer, receives input from the thalamus as it consists of stellate
neurons.
V. Internal pyramidal layer, output to spinal cord, brainstem and striatum.
VI. Multiform layer, output to thalamus.
The layers histologically, in terms of cell density and in size may differ depending on the
cortex; the motor cortex has a specialized V layer, the sensory cortex and special IV layer
and the associative cortex more a distinct III layer. So, there are different cytoarchitectural
areas related to function. The cortical layers themselves are arranged in columns, so they
have both horizontal and vertical connecting features.
Within the cerebral cortex, there are also connections between the hemispheres, known as
commissural connections. Actually, any left-right structure is connected by commissural
fibers. Different cortical areas within a hemisphere have associative connections, the
cortico-cortical connections.
The association cortices have three main functions:
- Parallel processing of sensory information to unimodal association areas
- Unimodal sensory inputs converge to multimodal association
- Posterior parietal association areas are interconnected with frontal association
areas, which thus help to guide behavior.
The different association cortices:
- Parietal: atrophy leads to the inability to attend to objects or one’s own body in a
portion of space despite the fact that visual, motor and sensory activity remains
intact. So, deficits in attention, perception of motion, special localization.
- Temporal: atrophy leads to the inability to recognize and identify colors, faces,
objects, etc.
- Frontal: atrophy has various serious and devastating effects associated with the
functioning of the frontal cortex in:
o Restraint: impaired judgement, concentration, no restraint on socially
inappropriate responses
o Initiative: impaired curiosity, spontaneity, motivation, creativity.
o Order: impaired abstract reasoning, planning, organization, perspective
taking.
Chapter 30
Humans have two qualitatively different ways of storing memory, namely via:
