**3.1.2 Striatotalamhic and thalamocortical tracts**

There are two different striatal pathways: one is direct and projects to the internal pallidus globus and substantia nigra pars reticulata; and the indirect going to the external globus pallidus. Both are inhibitory and mediated by GABA and neuroactive peptide. Integration of pathways inhibitory direct and indirect excitatory takes place at the internal globus pallidus and substantia nigra pars reticulata. Internal globus pallidus projects to thalamus through inhibitors GABA fibers.

The effects of facilitation played by the direct route or suppression maintained by the indirect on the outputs of the thalamus to the cortex influences movement and cognitive processing. Deinhibition of thalamic neurons results in hyperexcitability of the projections from the thalamus to the motor cortex leading to tics.
