Lecture 2- Forebrain and Limbic System Flashcards
The forebrain includes the… which is the thalamus, hypothalamus, epithalamus and subthalamus and the…. and the …. which is the hippocampus, hypothalamus and amygdala
Diencephalon
Internal Capsule
Limbic System
The pineal gland and habenula are part of the
epithalamus
The thalamus is considered the gateway to the…
cortex
The anterior division of the thalamus includes the… nucleus
anterior
The medial division of the thalamus includes the… nucleus
Dorsomedial (aka medial dorsal)
The lateral division of the thalamus is divided into
a dorsal and ventral tier
The dorsal tier of the lateral division of the thalamus contains these 2 nuclei:
Lateral dorsal (LD) Lateral posterior (LP) pulvinar
The ventral tier of the lateral division of the thalamus includes these 6 nuclei:
Ventral anterior (VA) Ventral lateral (VL) Vent post. lat (VPL) Vent post med (VPM) Lateral geniculate (LGN) Medial geniculate (MGN)
geniculate also called body
Besides anterior, medial and lateral, the thalamus has these 3 nuclei
intralaminar
reticular nucleus
midline nuclei
… subdivision of the thalamus is the largest
lateral
the subdivisions of the thalamus are defined by the…
internal medullary lamina (IML)
The anterior subdivision of the thalamus sits in a split in the…
IML
All thalamic nuclei (except….) are based on the same general theme and have 2 different population of neurons:
- reticular
- projection neurons and interneurons
*proportions vary
There are 2 basic types of thalamic inputs:
… inputs which convey info at thalamic nucleus passes on nearly directly to cortex. (example: ML to VPL or optic tract to LGN)
and … inputs where the thalamic nucleus contributes to the info it recieves before it is passed on to cortex
- specific
- regulatory
there are 3 categories of thalamic nuclei based on patterns of outputs and specific inputs
- Relay nuclei
- Association nuclei
- Intralaminar and midline nuclei
… nuclei recieve well defined input from a subcortical source (ex. medial lemniscus) and project to a well-defined area of cortex (ex. somatosensory cortex)
Relay
…nuclei recieve specific inputs from association cortex (ex. prefrontal cortex) and project back
association
…. nuclei recieve distinct set of specific inputs (basal ganglia, limbic structures) and project to cortex, BG and limbic structures
intralaminar and midline
The… is an important source of regulatory input to thalamus and has no projections to cortex (unlike all other thalamic nuclei)
reticular nucleus
Input to the reticular nucleus is from
cortex and thalamus
Output of reticular nucleus
inhibitory axons to thalamus
The… is a sheet of neurons that covers thalamus and that axons must traverse to enter/leave thalamus and send collaterals to it
reticular nucleus
sensory, motor and limbic systems have… nuclei
relay
relay nuclei of sensory
VPL and VPM
relay nuclei of motor
VA and VL
relay nuclei of limbic
Anterior and LD
specific inputs of anterior nucleus and cortical output
specific inputs: mammillothalamic tract, hippocampus
output: cingulate gyrus
Specific inputs of Lateral Dorsal (LD) nucleus and cortical output
specific inputs: hippocampus
output: cingulate gyrus
Specific inputs of VA/VL nuclei and cortical output
specific inputs:
BG (mostly VA)
cerebellum (mostly VL)
output: motor areas
Specific inputs of VPL nucleus and cortical output
specific inputs: Medial lemniscus, spinothalamic tract (ALP)
output: somatosensory cortex
Specific inputs of VPM nucleus and cortical output
specific inputs: trigeminal system
output: somatosensory cortex
AND
input: central tegmental tract (taste)
output: insula
Specific inputs of MGN nucleus and cortical output
input: branchium of inferior colliculous
output: auditory cortex
Specific inputs of LGN nucleus and cortical output
input: optic tract
output: visual cortex
… and… are main association nuclei
DM and Pulvinar
Parietal-occipital-temporal: pulvinar-LP complex function
largely unknown; may be involved in visual perception or attention
Prefrontal: DM function
foresight
DM specific input and cortical output
input: prefrontal cortex, olfactory and limbic structures (amygdala)
output: prefrontal cortex
LP specific inputs and cortical output
input: parietal lobe
output: parietal cortex
Pulvinar specific inputs and cortical output
input: parietal, occipital and temporal lobes
output: same
The most lateral part of the internal capsule is the
putamen
The lenticular nucleus is made up of the… and…
putamen and globus papllidus of the IC
… and … fibers pass through the IC.
thalamocortical and corticothalamic
*almost al fibers going to and from the cortex pass thru
The internal capsule collects and forms … down which corticopontine, corticobulbar and corticospinal fibers descend
cerebral peduncle
Internal capsule has 5 parts based on relationship to lenticular nucleus…
- anterior limb
- posterior limb
- genu
- retrolenticular
The anterior limb of the IC is made up from
lenticular nucleus and caudate
The posterior limb of the IC is made up of
lenticular nucleus and thalamus