Physiological plasticity of single neurons in auditory cortex of the cat during acquisition of the pupillary conditioned response: I. Primary field (AI).

Abstract

The effects of conditioning on the discharges of single neurons in primary auditory cortex (AI) were determined during acquisition of the pupillary conditioned response in chronically prepared cats. Acoustic stimuli (1-s white noise or tone) were presented with electrodermal stimulation unpaired during a sensitization control phase followed by pairing during a subsequent conditioning phase. Stimulus constancy at the periphery was ensured by the use of neuromuscular blockade. Discharge plasticity developed rapidly for both evoked and background activity, the former attaining criterion faster than the latter. The pupillary dilation conditioned response was acquired at the same rate as were changes in evoked activity (i.e., 10-15 trials) and faster than background activity (i.e., 20-25 trials). Increases in background activity were correlated with increasing level of tonic arousal, as indexed by pretrial size of the pupil.

Plasticity in the Rat Posterior Auditory Field Following Nucleus Basalis Stimulation

“…Long-term operant training can also cause frequencyspecific plasticity in secondary cortical areas (Polley et al 2006). Classical conditioning shifts receptive fields in both primary and secondary auditory cortices toward the conditioned stimulus (Diamond andWeinberger 1984, 1986;Weinberger et al 1984). A greater proportion of neurons in secondary cortical areas is altered by classical conditioning compared with A1 (Diamond and Weinberger 1984;Weinberger et al 1984).…”

Associative representational plasticity in the auditory cortex: resolving conceptual and empirical problems

“…added] tends to neglect two pieces of experimental evidence which are either explicitly mentioned in some of these studies or, in other cases, can be taken from the published figures. The first is the existence of sometimes large changes in toneevoked activity in response to frequencies other than the CS Weinberger, 1986, 1989); the other is the existence of reduced CS responses after training [9,10]." [14], [page 1014].…”

“…O&S are referring to decreased responses to the CS in single unit studies of plasticity during training trials in A1 and also secondary auditory cortex (A2), before we had started to use the unified design to study RF plasticity [9,10].…”

“…1 Standard training, in which recordings are obtained only during training trials, e.g., [10]. 2 Unified design (see text).…”

A computational model of mechanisms controlling experience-dependent reorganization of representational maps in auditory cortex

“…A wide variety of experience-dependent changes in spectral sensitivities can be induced by either basal forebrain stimulation or behavioral training, including (1) increased responses to a conditioned tone pip (Bakin & Weinberger, 1990; D. M. Diamond & Weinberger, 1986;Edeline & Weinberger, 1993a;Weinberger et al, 1993); (2) decreased responses to a conditioned tone pip (D. M. Kraus & Disterhoft, 1982;Ohl & Scheich, 1996Weinberger, Hopkins, & Diamond, 1984); (3) increased responses to frequencies surrounding a conditioned or stimulated tone pip (Bjordahl et al, 1998; D. M. Diamond & Weinberger, 1989;Metherate & Weinberger, 1989;Ohl & Scheich, 1996; (4) decreased responses to frequencies other than that of a conditioned tone pip (Bakin, South, & Weinberger, 1996;Bakin & Weinberger, 1990;Edeline & Weinberger, 1993b;Weinberger et al, 1993); (5) changes in the size (e.g., bandwidth) of the receptive field (Edeline & Weinberger, 1993b;Kilgard & Merzenich, 1998a;Weinberger et al, 1993); and (6) general increases/decreases in neural responsiveness (Bakin, Lepan, & Weinberger, 1992;Bakin & Weinberger, 1990; D. M. Diamond & Weinberger, 1989;Edeline & Weinberger, 1993a). Cases in which neurons show no statistically significant changes in responsiveness to a conditioned tone pip have also been observed (see, e.g., Edeline & Weinberger , 1993b;Weinberger et al, 1984). Although the wide range of reported changes in receptive fields can be attributed,in part, to differing methodologies,many varieties of changes have been reported in individual studies.…”