The Basal Ganglia
Components of the limbic system
cortical and subcortical structures
determined by a tally (and averaging) of votes.
direction of movement
Substantra Nigra has __________ that project to the striatum, synapsing with inhibitory neurons projecting from striatum to internal GP.
dopamine releasing neurons
Relay station for info. between cortical areas and hippocampus
entorhinal cortex
learning and memory
hippocampus
The connection between the _______________ and the _________ allow for connection of endocrine, visceral, emotional, and voluntary responses to the environment.
hypothalamus neocortex
cortex that overlies the hippocampus
parahippocamual gyrus
Name the disorders of the basal ganglia.
parkinson's huntington's tourette's obsessive compulsive disorder
The pathways of the basal ganglia communicate via...
pre and post synaptic neurons to different locations, communicating via neurotransmitters.
The ______ and the _____ are the input nuclei to the basal ganglia. They receive mostly _______ input from the cortical and subcortical structures.
putamen caudate nucleus excitatory
reward mechanisms
septal nuclei
___________ contains dopaminergic neurons that project to the putamen, caudate, and subthalamic nucleus.
substantia nigra
During the direct pathway these two are known to fine tune movements.
substantia nigra subthalamic nucleus
Excites the substantra nigra..
subthalamic nucleus
____________ receives affarents from bith the cortex and other basal ganglia structures. It's output is excitatory through glutamatergic projections to the globus pallidus and the substantia nigra. Is important in the connectivity and can be describes as the "clock" of the basal ganglia defining the output rhythm.
subthalamic nucleus
List the steps of the direct pathway.
1) excitatory neuron goes from motor cortex to the striatum and releases glutamate 2)synapses with inhibitory neuron that goes to the internal globus pallidus releasing GABA ( this leads to more excitation of the striatum, causing further inhibition of the internal GP). The thalamus is usually inhibited by the internal GP, when internal GP is inhibitied, it will release the inhibition of the thalamus. 3)The thalamus is activated and is able to send messages to the motor cortex to move somatic musculature.
The basal ganglia directs 3 things, list them.
1)motor expression of emotions 2)direction and amplitude of movement: - controls and regulates activities of the premotor and motor cortex. Enables voluntary movements to be performed smoothly. 3)Decisions about movement: -helps determine the decision of which of several possible behaviors to execute at any given time
_________ facilitates target-oriented and efficient behavior
Direct pathway
The parahippocamual gyrus consists of:
Entorhinal cortex (anterior portion) Uncus (most anteromedial portion)
Presynaptic neuron releases ____ for inhibition, or ________ for excitation of postsynaptic neuron.
GABA glutamate
Ring of cortex on the medial surface of the brain that spans across aspects of the frontal, parietal, and temporal lobes.
Limbic lobe location
Explain the direct pathway of the basal ganglia.
The thalamus is usually under inhibition (thalamus is suppressed unless instructed to not be suppressed). The direct pathway takes away the "inhibition" of the thalamus to allow it to be more active. The thalamus then relays information to the primary motor cortex in the frontal lobe for movement.
Explain the pathway of substantra nigra.
When the substantra nigra is more active, more dopamine is released, exciting the striatum and inhibiting the internal GP. Further inhibition of the internal GP allows the thalamus to become more active.
emotions and drives
amygdala
involved in complex motor planning
associative circuit
Name the circuits of the basal ganglia
associative circuit motor circuit the coding of movement
limbus is latin for
border
The basal ganglia is made up of a collection of neurons called nuclei (list them).
caudate putamen globus pallidus (internal & external) substantra nigra subthalamic nucleus
Together comprise the straitum
caudate and putamen
superior to the corpus collosum
cingulate gyrus
Cortical (limbic lobe) structures in the limbic system:
cingulate gyrus subcallosal gyrus parahippocamual gyrus
cortex structures in the limbic system are connected by subcortical fiber known as...
cingulum
Basal Ganglia
Controls selection and initiation of willed movements
Subcortical structures of limbic system:
Hippocampus Amygdala Septal nuclei
__________ suppresses superfluous behaviors that are not related to a targeted behavior.
Indirect pathway
many cells active for every movement. Activity of each cell represents a single "vote".
Motor cortex
Components of basal ganglia:
Substantra Nigra Globus pallidus Caudate Putamen Substantra Nigra Subthalamic nucleus
Direct Pathway: excitatory connection from cortex to putamen cortical activation activates putamen inhibits globus pallidus release thalamus from inhibition T/F
True
"Hook" overlies amygdala and anterior hippocampus
Uncus
Every cell in the striatum is an ___________ because a single cell receives input from multiple sources.
integrator
The ___________ is comprised of the globus pallidus and the putamen.
lentiform nucleus
The limbic system functions are:
motivation drive emotions memory emotional learning behavior reward
involved in regulating gaze and orientation of the eyes
motor circuit
_______ is not part of basal ganglia but works with it to control movement.
thalamus
Movement of direction encoded by collective activity of neurons.
the coding of movement