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