Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2016 Dec 15;5(4):303–331. doi: 10.3233/JHD-160221

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

IOS Press and the authors. All rights reserved

This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial (CC BY-NC 4.0) License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

PMC Copyright notice

Fig.1 — Schematic illustration of basal ganglia circuitry. Striatal medium spiny neurons (MSNs) receive excitatory corticostriatal input from IT and PT pyramidal neurons in cerebral cortex. Intra-telencephalic (IT) neurons preferentially activate substance P/D₁ receptor (SP/D₁R) MSNs that project to the internal globus pallidus and sustantia nigra pars reticulata (GPi/SNpr) forming the direct pathway. Pyramidal tract (PT) neurons activate enkephalin/D₂ receptor (ENK/D₂R) MSNs that form the indirect pathway and send projections to the external globus pallidus (GPe). GPe neurons in turn send axons to the subthalamic nucleus (STN), which projects to GPi/SNpr. GPi/SNpr is the basal ganglia output system that integrates direct and indirect pathway information and sends it back to cortex via thalamus.