We compared the spatial tuning properties of neurons in two fields [primary auditory cortex (A1) and posterior auditory field (PAF)] of cat auditory cortex. Broadband noise bursts of 80-ms duration were presented from loudspeakers throughout 360 degrees in the horizontal plane (azimuth) or 260 degrees in the vertical median plane (elevation). Sound levels varied from 20 to 40 dB above units' th...

A fundamental question in neuroscience is how neurons perform precise operations despite inherent variability. This question also applies to neuromorphic engineering, where low-power microchips emulate the brain using large populations of diverse silicon neurons. Biological neurons in the auditory pathway display precise spike timing, critical for sound localization and interpretation of comple...

abiotic stresses and lack of nutrients are one of the most important factors in reducing the crop yield.  vigorous and developed roots can facilitate uptake of water and nutrients more efficiently making it essential for enhancing the yield. association mapping is currently one of the approaches for detecting quantitative trait loci (qtls) influencing complex traits. this approach was used to d...

It is well accepted that the brain's computation relies on spatiotemporal activity of neural networks. In particular, there is growing evidence of the importance of continuously and precisely timed spiking activity. Therefore, it is important to characterize memory states in terms of spike-timing patterns that give both reliable memory of firing activities and precise memory of firing timings. ...

Sensory and cognitive processing relies on the concerted activity of large populations of neurons. The advent of modern experimental techniques like two-photon population calcium imaging makes it possible to monitor the spiking activity of multiple neurons as they are participating in specific cognitive tasks. The development of appropriate theoretical tools to quantify and interpret the spikin...

Neurons are sensitive to the relative timing of inputs, both because several inputs must coincide to reach spike threshold and because active dendritic mechanisms can amplify synchronous inputs. To determine if input synchrony can influence behavior, we trained mice to report activation of excitatory neurons in visual cortex using channelrhodopsin-2. We used light pulses that varied in duration...

A current-source density (CSD) analysis was carried out in the CA 1 region of the hippocampal slice (1) to determine the pattern of current flow in pyramidal cells upon orthodromic stimulation and (2) to test the hypothesis that EPSP-to-spike potentiation is produced by an alteration in this distribution of current sinks and/or sources. The results indicated that 2 sinks occur near the cell bod...

We propose a spiking network model capable of performing both approximate inference and learning for any hidden Markov model. The lower layer sensory neurons detect noisy measurements of hidden world states. The higher layer neurons with recurrent connections infer a posterior distribution over world states from spike trains generated by sensory neurons. We show how such a neuronal network with...

drought stress is considered as one of the main important factors reducing field crop yield, thus leading researchers to study the related physiological characteristics may reduce drought effects. this experiment was conducted in research farm of seed and plant improvement institute (spii) in karadj, arak and jolgeh rokh for three cropping seasons (2008-2011) to evaluate drought tolerance of br...

In many species, neurons with highly selective stimulus-response properties characterize higher order sensory areas and/or sensory motor areas of the CNS. In the songbird nuclei, the responses of HVC (used as a proper name) neurons during playback of the bird's own song (BOS) are probably one of the most striking examples of selectivity for natural stimuli. We examined here to what extent spike...