HMB320H1 Lecture 6: HMB320 Lectures (6-8)
Document Summary
Balance between stop and go pathway creates control movements. Direct connections between cortex"s upper motor neurons lower motor neurons. Basal ganglia does not have direct connections to lower motor neurons. Basal ganglia has other functions i. e. cognitive, mood. Basal ganglia cortex lower motor neurons. Gpi globus pallidus interna | snr substantia nigra pars reticularis (gpi + snr both have similar functions) Basal ganglia baseline conditions, the thalamus is strongly inhibited = chronic inhibition. Basal ganglia go pathway = disinhibition of thalamus. Motor cortex --> striatum --| gpi/snr --| thalamus --> motor cortex --> lmn (disinhibition of thalamus) Basal ganglia modulatory pathway, from snc that enhances go pathway. Snc (daergic neurons) --> striatum --| gpi/snr --| thalamus --> motor cortex --> lmn (disinhibition of thalamus, enhances go pathway) Gpe --| stn --> gpi/snr (stn causes more inhibition of thalamus, gpe stops stn from inhibiting)
