Metabotropic XXXX receptor 5 shows different patterns of localization within the parallel visual pathways in macaque and squirrel monkeys.

@entity2227 @entity2438 @entity10092 @entity161 @entity3505
UNASSIGNED: @entity2227 is used as an excitatory neurotransmitter by the koniocellular (K), magnocellular (M), and parvocellular (P) pathways to transfer signals from the primate lateral geniculate nucleus (LGN) to primary visual cortex (V1). @entity2227 acts through both fast ionotropic receptors, which appear to carry the main sensory message, and slower, modulatory metabotropic receptors (mGluRs). In this study, we asked whether @entity10092 relates in distinct ways to the K, M, and P LGN axons in V1. To answer this question, we used light microscopic immunocytochemistry and preembedding electron microscopic immunogold labeling to determine the localization of @entity10092 within the layers of V1 in relation to the K, M, and P pathways in macaque and squirrel monkeys. These pathways were labeled separately via @entity3505 germ agglutinin-horseradish peroxidase (WGA-HRP) injections targeting the LGN layers. @entity10092 is of interest because it: 1) has been shown to be expressed in the thalamic input layers; 2) appears to be responsible for some types of oscillatory firing, which could be important in the binding of visual features; and 3) has been associated with a number of sensory-motor gating-related pathologies, including @entity161 and @entity2438 . Our results demonstrated the presence of @entity10092 in the neuropil of all V1 layers. This protein was lowest in IVCa (M input) and the infragranular layers. In layer IVC, @entity10092 also was found postsynaptic to about 30% of labeled axons, but the distribution was uneven, such that postsynaptic @entity10092 label tended to occur opposite smaller (presumed P), and not larger (presumed M) axon terminals. Only in the K pathway in layer IIIB, however, was @entity10092 always found in the axon terminals themselves. The presence of @entity10092 in K axons and not in M and P axons, and the presence of @entity10092 postsynaptic mainly to smaller P and not larger M axons suggest that the response to the release of @entity2227 is modulated in distinct ways within and between the parallel visual pathways of primates.
