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 fluorescence 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 laterally-dominated 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.

Whole-Brain Direct Inputs to and Axonal Projections from Excitatory and Inhibitory Neurons in the Mouse Primary Auditory Area / 神经科学通报·英文版

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 fluorescence 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 laterally-dominated 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.

Whole-Brain Mapping the Direct Inputs of Dorsal and Ventral CA1 Projection Neurons.

The CA1, an important subregion of the hippocampus, is anatomically and functionally heterogeneous in the dorsal and ventral hippocampus. Here, to dissect the distinctions between the dorsal (dCA1) and ventral CA1 (vCA1) in anatomical connections, we systematically analyzed the direct inputs to dCA1 and vCA1 projection neurons (PNs) with the rabies virus-mediated retrograde trans-monosynaptic tracing system in Thy1-Cre mice. Our mapping results revealed that the input proportions and distributions of dCA1 and vCA1 PNs varied significantly. Inside the hippocampal region, dCA1 and vCA1 PNs shared the same upstream brain regions, but with distinctive distribution patterns along the rostrocaudal axis. The intrahippocampal inputs to the dCA1 and vCA1 exhibited opposite trends, decreasing and increasing gradually along the dorsoventral axis, respectively. For extrahippocampal inputs, dCA1 and vCA1 shared some monosynaptic projections from certain regions such as pallidum, striatum, hypothalamus, and thalamus. However, vCA1, not dCA1, received innervations from the subregions of olfactory areas and amygdala nuclei. Characterization of the direct input networks of dCA1 and vCA1 PNs may provide a structural basis to understand the differential functions of dCA1 and vCA1.

Evaluation of energy use and carbon dioxide emissions from the consumption of fossil fuels and agricultural chemicals for paste tomato cultivation in the Bursa region of Turkey.

This study was aimed to determine the fossil fuel consumption, energy use, and carbon dioxide (CO2) emissions in per unit production area (ha) considering the petroleum products (PP) directly used and the chemical fertilizers and pesticides for the cultivation of paste tomatoes in open-field conditions in Bursa region of Turkey. The primary data of the study consisted of data collected by making face-to-face surveys with the producers of paste tomatoes in the Bursa region. The direct energy inputs and CO2 emissions related to diesel fuel and lubricant oil consumptions of engines of agricultural tractors for cultivation operations and the indirect energy inputs and CO2 emissions related to the manufacturing of chemical fertilizers and plant growth regulators used for plant nutrition and pesticides used for plant protection were determined for paste tomato cultivation. A total of 288.6 L diesel fuel and 0.067 L lubrication oil are consumed per hectare when using tools and machinery in paste tomato production. A total of 408 kg of chemical fertilizers and 15.5 kg of pesticides are used per hectare in paste tomato production in the Bursa region of Turkey. A total of 2343.45 MJ/ha and 2700.5 MJ/ha indirect energy is used in the application of chemical fertilizers and pesticides, respectively. A total of 792.43 kg and 0.189 kg CO2 is released as a result of diesel fuel and lubricant oil consumptions. For the production of one kilogram of paste tomato, 2.68 grams (g) diesel fuel and lubricating oil, 175.02 kilojoules (kJ) of energy is consumed, and 15.88 g CO2 is released in the Bursa region of Turkey.

Cell-Type-Specific Whole-Brain Direct Inputs to the Anterior and Posterior Piriform Cortex.

The piriform cortex (PC) is a key brain area involved in both processing and coding of olfactory information. It is implicated in various brain disorders, such as epilepsy, Alzheimer's disease, and autism. The PC consists of the anterior (APC) and posterior (PPC) parts, which are different anatomically and functionally. However, the direct input networks to specific neuronal populations within the APC and PPC remain poorly understood. Here, we mapped the whole-brain direct inputs to the two major neuronal populations, the excitatory glutamatergic principal neurons and inhibitory γ-aminobutyric acid (GABA)-ergic interneurons within the APC and PPC using the rabies virus (RV)-mediated retrograde trans-synaptic tracing system. We found that for both types of neurons, APC and PPC share some similarities in input networks, with dominant inputs originating from the olfactory region (OLF), followed by the cortical subplate (CTXsp), isocortex, cerebral nuclei (CNU), hippocampal formation (HPF) and interbrain (IB), whereas the midbrain (MB) and hindbrain (HB) were rarely labeled. However, APC and PPC also show distinct features in their input distribution patterns. For both types of neurons, the input proportion from the OLF to the APC was higher than that to the PPC; while the PPC received higher proportions of inputs from the HPF and CNU than the APC did. Overall, our results revealed the direct input networks of both excitatory and inhibitory neuronal populations of different PC subareas, providing a structural basis to analyze the diverse PC functions.