In an effort to understand better how the zona incerta may influence neocortical activity, this study has examined the patterns of projection that this nucleus has to the dorsal thalamus, the "gateway" to the neocortex. To this end, Sprague-Dawley rats were anaesthetised with Ketamil (100 mg/kg) and
Evidence for a glutamatergic projection from the zona incerta to the basal ganglia of rats
✍ Scribed by Claire E. Heise; John Mitrofanis
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 783 KB
- Volume
- 468
- Category
- Article
- ISSN
- 0021-9967
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
This study explores the organisation and neurochemical nature of the projections from the zona incerta (ZI) to the basal ganglia. Sprague‐Dawley rats were anaesthetised with ketamine (100 mg/kg) and Rompun (10 mg/kg), and injections of cholera toxin subunit B were made into each of the following nuclei: the ZI, the substantia nigra (SN), the pedunculopontine tegmental nucleus (PpT), and the entopeduncular nucleus (Ep). Brains were aldehyde fixed, sectioned, and processed using standard methods. Tracer‐labelled sections were then doubly labelled with antibodies to glutamate (Glu), nitric oxide synthase (NOS), parvalbumin (Pv), or glutamic acid decarboxylase (GAD; the latter two are markers for GABAergic cells); these neurochemicals characterise most types of ZI cells. After ZI injections, labelling was nonuniform across the different basal ganglia nuclei. The bulk of labelling, both anterograde and retrograde, was seen in the SN and PpT and, to a lesser extent, within the other nuclei of the basal ganglia (e.g., caudate‐putamen, globus pallidus, subthalamus, Ep). In the SN, labelling was found in both major parts of the nucleus, the pars compacta and pars reticulata. Within the PpT, however, the bulk of labelling was limited to only one of the two sectors of the nucleus, namely, the pars dissipata (PpTd). The pars compacta of the PpT (PpTc) remained largely free of labelled profiles. After CTb injections into three basal ganglia nuclei (SN, PpT, Ep), most labelled cells in the ZI were glutamate^+^ and very few were NOS^+^ or γ‐aminobutyric acidergic. Overall, the results indicate that the ZI is in a position to influence preferentially the activity of the SN and PpTd of the basal ganglia via an excitatory, glutamatergic input. J. Comp. Neurol. 468:482–495, 2004. © 2003 Wiley‐Liss, Inc.
📜 SIMILAR VOLUMES
The subcutaneous LDSO of picrotoxin of the adult male albino rat was 87 per cent higher than for the female (5.48 versus 2.82 mg./Kg.); 458 rats were used in these determinations. No sex variation, however, was found in case of albino mice, guinea pigs, or Syrian hamsters. Castration of adult males