Basal ganglia 101
description
Transcript of Basal ganglia 101
Basal Ganglia 101
Journal Club
September 9, 2010
Anatomy
Bird’s eye view
Basal Ganglia Components
• Neostriatum: Caudate nucleus and putamen
• Globus Pallidus: externa and interna
• Substantia Nigra: pars compacta and pars reticulata
• Subthalamic nucleus
• Pedunculopontine nucleus
Caudate nucleus and Putamen
• Receives input from cortex, limbic structures, thalamus, and SNc
• Medium spiny neurons– GABAergic
• Sends output to globus pallidus externa and interna
Globus Pallidus interna (GPi) and Substantia nigra pars reticulata (SNr)
• Output center for the Basal Ganglia
• Receives input from striatum,GPe, SNc and subthalamic nucleus
• Sends efferents to thalamus and brainstem
• GABAergic
Globus Pallidus externa (GPe) and Substantia nigra pars compacta (SNc)
• Modulator• Receives input
from striatum• Sends efferents
to subthalamic nucleus and GPi
Subthalamic Nucleus
• Internal modulator• Receives input from
striatum, frontal cortex, thalamus, brainstem nuclei
• Send efferents to GPi and GPe
• Glutaminergic
Peduncular nucleus (PPN)
• Midbrain locomotor • Cholinergic and
glutaminergic cells
Circuitry
• Information processing loop• Input from cortex, limbic structures,
brainstem nuclei• Output from globus pallidus interna or
substantia nigra par reticulata to thalamus
• Relayed back to cortex
Direct Pathway
•Cortex Striatum (glutaminergic, excitatory signal)
•Striatum GPi/SNr (GABAergic, inhibatory signal)
•GPi/SNr Thalamus (GABA, inhibitory signal)
• Thalamus Cortex (glutaminergic, excitatory signal)
Indirect Pathway•Cortex Striatum (glutaminergic, excitatory signal)•Striatum GPe (GABAergic, inhibatory signal)
•GPe Subthalamic Nucleus (GABAergic, inhibitory signal)• STN GPi/SNr (glutaminergic, excitatory signal)
•GPi/SNr Thalamus (GABAergic, inhibitory signal
•Thalamus Cortex (glutaminergic, excitatory signal)
Reality?
Parallel Loops