HMB320H1 Lecture Notes - Lecture 6: Dorsal Root Ganglion, White Matter, Ventral Posterior Nucleus
Document Summary
The basal ganglia modifies the behaviour of motor neurons without directly synapsing onto them. Controlled actions requires both go" and stop" signals to have a balance of elicited movements. The basic circuit: modulating the stop and go pathways. Modulatory input from the substantia nigra pars compacta synapses directly onto two distinct populations of cells within the striatum. There are two populations of cells within the striatum: cells involved with the go" pathway. Activated by dopamine: cells involved with the stop" pathway. Enhances activity in the go pathway (d1 receptors) Inhibits activity in the stop pathway (d2 receptors) The combined effect of both actions is to enhance action of the cerebral cortex. Damage to the basal ganglia results in hyperkinetic or hypokinetic disorders depending on which anatomical structure is affected. The functional loss that results from damage to the basal ganglia depends on which anatomical part is affected. Damage to the striatum results in huntington"s disease.
