Whole-Brain Direct Inputs to and Axonal Projections from Excitatory and Inhibitory Neurons in the Mouse Primary Auditory Area

Neurons in the primary auditory area(AUDp)innervate multiple brain regions with long-range projections while receiving informative inputs for diverse functions.However,the brain-wide connections of these neurons have not been comprehensively investigated.Here,we simultaneously applied virus-based anterograde and retrograde tracing,labeled the connections of excitatory and inhibitory neurons in the mouse AUDp,and acquired whole-brain information using a dual-channel fuorescence micro-optical sectioning tomography system.Quantified results showed that the two types of neurons received inputs with similar patterns but sent heterogeneous projections to downstream regions.In the isocortex,functionally different areas consistently sent feedback-dominated projections to these neurons,with concomitant laterallydominated projections from the sensory and limbic cortices to inhibitory neurons.In subcortical regions,the dorsal and medial parts of the non-lemniscal auditory thalamus(AT)were reciprocally connected to the AUDp,while the ventral part contained the most fibers of passage from the excitatory neurons and barely sent projections back,indicating the regional heterogeneity of the AUDp-AT circuit.Our results reveal details of the whole-brain network and provide new insights for further physiological and functional studies of the AUDp.

Study on Trends of Change in Direct Input Coefficients of China

The objective of this paper is to study the trends of change in direct input coefficients of China. We reconstructed a time series of input\|output tables of China with 18 sectors for 1981, 1987, 1990, 1992 and 1995 at constant prices and current prices, and the tables for developed region, middle developed region and underdevelopd region. On the basis of these tables we found seven important trends on change in China′s direct input coefficients.