Optical imaging of neural activity in multiple auditory cortical fields of guinea pigs

Abstract

Neural activity of multiple fields in the auditory cortex of anesthetized guinea pigs in response to pure tones was visualized by optical recording using a voltage-sensitive dye (RH795). Ten auditory fields were identified based on the tonotopic organization and response latency: the core fields consisting of the primary (AI) and secondary (AII) fields and surrounding belt areas consisting of dorso-anterior (DA), dorsal (D), dorso-posterior (DP), posterior (P), ventro-posterior (VP), ventro-medial (VM), ventro-anterior (VA) and ventral (V) fields. Tonotopic organization was observed in all the fields apart from DA, D, DP and V. Spatio-temporal displays suggest that the auditory information spreads from the core fields of AI and AII to belt fields via three distinct (dorsocaudal, caudal and ventrorostral) pathways.

Optical imaging of plastic changes induced by fear conditioning in the auditory cortex

“…In contrast, in field DC, cells are arranged from caudal to rostral direction with increasing sound frequency. Figure 3 shows a trend of mirror-symmetrical tonotopic mapping in fields A and DC, similar to previous findings on the basis of microelectrode methods (Redies et al 1989;Wallace et al 2000) and optical imaging (Horikawa et al 2001).…”

“…The above hypothesis is based on this evidence. To further substantiate this hypothesis, we employed the optical imaging method with a voltage sensitive dye (Cohen et al 1978;Grinvald et al 1988;Horikawa et al 1996Horikawa et al , 2001). The optical imaging method has recently attracted attention as one of the useful methods for investigating the dynamic function of the brain.…”

Multiparametric Auditory Receptive Field Organization Across Five Cortical Fields in the Albino Rat

“…4). However, in light of findings from more recent, higher-resolution mapping of the guinea pig auditory cortex, these injections were likely made into an isofrequency contour that spanned AI and the immediately adjacent ventral field (Horikawa et al 2001;Nishimura et al 2007) in a fashion similar to that in our study. Based on this interpretation, the present results from VAF and AI in the rat are in perfect concordance with the thalamocortical connectivity patterns in the guinea pig.…”

“…An auditory core composed of AI and at least two tonotopically organized fields ventral to AI were previously described in the cat (Andersen et al 1980;Reale and Imig 1980), ferret (Bizley et al 2005;Nelken et al 2004), and gerbil (Thomas et al 1993). A tonotopically organized field with mirror-symmetry to AI was documented either anterior, in the case of the macaque monkey (Morel et al 1993), cat (Andersen et al 1980;Reale and Imig 1980), ferret (Bizley et al 2005;Nelken et al 2004), and mouse (Linden et al 2003;Stiebler et al 1997); or posterior in the case of the guinea pig (Horikawa et al 2001;Wallace et al 2000); or a combination of an anterior and dorsoposterior fields in the case of the rat and gerbil (Doron et al 2002;Horikawa et al 1988;Rutkowski et al 2003;Thomas et al 1993).…”

Tonotopic organization of the human auditory cortex probed with frequency-modulated tones

“…A fundamental organizational principle of the central auditory system is the frequency specific (tonotopic) representation of neuronal populations (de Ribaupierre, 1997;Horikawa et al, 2001;Schreiner et al, 2000), preserving the arrangement of hearing receptors in the inner ear (high-to-low frequency representation from base to apex). This means that neurons processing information from neighbouring hair cells are also neighbours on a tonotopic map.…”