Afferent Projections to Area Prostriata of the Mouse.

Jin-Meng Hu,Sheng-Qiang Chen,Song-Lin Ding,Chang-Hui Chen

doi:10.3389/fnana.2020.605021

Abstract

Area prostriata plays important roles in fast detection and analysis of peripheral visual information. It remains unclear whether the prostriata directly receives and integrates information from other modalities. To gain insight into this issue, we investigated brain-wide afferent projections to mouse prostriata. We find convergent projections to layer 1 of the prostriata from primary and association visual and auditory cortices; retrosplenial, lateral entorhinal, and anterior cingulate cortices; subiculum; presubiculum; and anterior thalamic nuclei. Innervation of layers 2–3 of the prostriata mainly originates from the presubiculum (including postsubiculum) and anterior midline thalamic region. Layer 5 of the prostriata mainly receives its inputs from medial entorhinal, granular retrosplenial, and medial orbitofrontal cortices and anteromedial thalamic nucleus while layer 6 gets its major inputs from ectorhinal, postrhinal, and agranular retrosplenial cortices. The claustrum, locus coeruleus, and basal forebrain provide relatively diffuse innervation to the prostriata. Moreover, Cre-dependent tracing in cortical areas reveals that the cells of origin of the prostriata inputs are located in layers 2–4 and 5 of the neocortical areas, layers 2 and 5 of the medial entorhinal cortex, and layer 5 of the retrosplenial cortex. These results indicate that the prostriata is a unique region where primary and association visual and auditory inputs directly integrate with many limbic inputs.

Highlights

Area prostriata (Pro) belongs to the limbic cortex, which is characterized by lack of granular layer 4 and existence of lamina dissecans (e.g., Sanides, 1969; Ding et al, 2003; Rockland, 2012)
Since strong and weak projections has recently been described from V1 and medial secondary visual cortex (V2M) to the Pro (L1–3), respectively (Lu et al, 2020), here we focus on the projections from association visual cortices [mainly lateral secondary visual cortex (V2L), postrhinal cortex (POR), and ectorhinal cortex (ECT) (i.e., Brodmann area 36)] to the Pro
Since Ntng2-Cre and Rbp4-Cre/gastrin-releasing peptide (Grp)-Cre are respectively expressed in L2 and L5 of the medial entorhinal cortex (MEC), these results suggest that subsets of neurons in L2 and L5 of the MEC are the major origins of the projections to the Pro

Summary

Introduction

Area prostriata (Pro) belongs to the limbic cortex, which is characterized by lack of granular layer 4 and existence of lamina dissecans (e.g., Sanides, 1969; Ding et al, 2003; Rockland, 2012). The Pro in both monkey and human brains was found to play important roles in fast analysis of information derived from the peripheral visual field (Yu et al, 2012; Mikellidou et al, 2017; Tamietto and Leopold, 2018). These functions are consistent with our recent finding that the rodent Pro receives strong afferent projections directly from the medial primary visual cortex (V1) which represents the peripheral visual field (Lu et al, 2020). We find that mouse Pro mainly receives and processes information from primary and secondary/association (we use the term ‘‘association’’ in this study) visual and auditory cortices, from the regions critical for spatial processing and navigation such as Sub, PrS, ATN, and medial entorhinal (MEC) and retrosplenial (RS) cortices and from the structures important for attention such as claustrum (Cla)

Objectives

Methods

Results

Conclusion