%0 Journal Article
%T The auditory cortex of the bat Phyllostomus discolor: Localization and organization of basic response properties
%A Susanne Hoffmann
%A Uwe Firzlaff
%A Susanne Radtke-Schuller
%A Britta Schwellnus
%A Gerd Schuller
%J BMC Neuroscience
%D 2008
%I BioMed Central
%R 10.1186/1471-2202-9-65
%X The auditory cortical area of P. discolor is located at parieto-temporal portions of the neocortex. It covers a rostro-caudal range of about 4800 ¦Ìm and a medio-lateral distance of about 7000 ¦Ìm on the flattened cortical surface.The auditory cortices of ten adult P. discolor were electrophysiologically mapped in detail. Responses of 849 units (single neurons and neuronal clusters up to three neurons) to pure tone stimulation were recorded extracellularly. Cortical units were characterized and classified depending on their response properties such as best frequency, auditory threshold, first spike latency, response duration, width and shape of the frequency response area and binaural interactions.Based on neurophysiological and neuroanatomical criteria, the auditory cortex of P. discolor could be subdivided into anterior and posterior ventral fields and anterior and posterior dorsal fields. The representation of response properties within the different auditory cortical fields was analyzed in detail. The two ventral fields were distinguished by their tonotopic organization with opposing frequency gradients. The dorsal cortical fields were not tonotopically organized but contained neurons that were responsive to high frequencies only.The auditory cortex of P. discolor resembles the auditory cortex of other phyllostomid bats in size and basic functional organization. The tonotopically organized posterior ventral field might represent the primary auditory cortex and the tonotopically organized anterior ventral field seems to be similar to the anterior auditory field of other mammals. As most energy of the echolocation pulse of P. discolor is contained in the high-frequency range, the non-tonotopically organized high-frequency dorsal region seems to be particularly important for echolocation.During the last decade, the bat P. discolor has been used increasingly for psychophysical and neurophysiological studies of echolocation [1-4]. P. discolor is medium-sized and forage
%U http://www.biomedcentral.com/1471-2202/9/65