Thalamic innervation of the direct and indirect basal ganglia pathways in the rat: Ipsi- and contralateral projections

Abstract

The present study describes the thalamic innervation coming from the rat parafascicular nucleus (PF) onto striatal and subthalamic efferent neurons projecting either to the globus pallidus (GP) or to the substantia nigra pars reticulata (SNr) by using a protocol for multiple neuroanatomical tracing. Both striatofugal neurons targeting the ipsilateral SNr (direct pathway) as well as striatal efferent neurons projecting to the ipsilateral GP (indirect pathway) were located within the terminal fields of the thalamostriatal afferents. In the subthalamic nucleus (STN), both neurons projecting to ipsilateral GP as well as neurons projecting to ipsilateral SNr also appear to receive thalamic afferents. Although the projections linking the caudal intralaminar nuclei with the ipsilateral striatum and STN are far more prominent, we also noticed that thalamic axons could gain access to the contralateral STN. Furthermore, a small number of STN neurons were seen to project to both the contralateral GP and PF nuclei. These ipsi-and contralateral projections enable the caudal intralaminar nuclei to modulate the activity of both the direct and the indirect pathway. J. Comp. Neurol. 483:143-153, 2005.

Contralateral disconnection of the rat prelimbic cortex and dorsomedial striatum impairs cue-guided behavioral switching

“…Disruption in this neural system could lead to failure in selecting an alternative response and instead lead to continually executing the same, now inappropriate, response pattern. Although the experimental findings suggest that the prelimbic cortex interacts with both the subthalamic nucleus and dorsomedial striatum to facilitate cue-guided behavioral switching, this does not rule out that the prelimbic cortex, or other prefrontal cortex areas, are functionally connected with other basal ganglia areas, i.e., the nucleus accumbens (Floresco et al 2006a) or intralaminar thalamic nuclei (Canteras et al 1990;Castle et al 2005;Brown et al 2010) to also enhance cue-guided behavioral switching. Future studies can more fully determine the network of brain areas that support cue-guided behavioral switching.…”

Deep Brain Stimulation of the Center Median-Parafascicular Complex of the Thalamus Has Efficient Anti-Parkinsonian Action Associated with Widespread Cellular Responses in the Basal Ganglia Network in a Rat Model of Parkinson's Disease

“…There are no data available about the anti-parkinsonian action of the Pf lesion in the rat, but a recent study showed no significant persistent motor improvement after CM/Pf lesion in the MPTP monkey model of PD (Lanciego et al, 2008). This lack of effect could be due to the fact that the CM/Pf lesion was performed unilaterally in a bilateral dopaminergic lesion model, whereas crossed projections from CM/Pf to STN and SNr have been reported (Marini et al, 1999;Castle et al, 2005). Another explanation is that reversal of the response to the dopamine lesion in SNr is a requisite for efficient beneficial action on forelimb akinesia.…”

Cortical and Thalamic Innervation of Direct and Indirect Pathway Medium-Sized Spiny Neurons in Mouse Striatum

“…Both direct and indirect pathway MSNs have been shown to receive synaptic input from the cortex (Somogyi et al, 1981;Hersch et al, 1995;Lei et al, 2004). Light microscopic studies have suggested that the same is true for thalamostriatal afferents (Lanciego et al, 2004;Castle et al, 2005). Electron microscopic studies in primates have suggested that afferents from the centromedian nucleus (CM) of the thalamus preferentially innervate direct pathway MSNs (Sidibé and Smith, 1996).…”