Algorithms for computing spike time distance and point process prototypes with application to feline neuronal responses to acoustic stimuli.

The spike-time distance metric and the prototype of a collection of point patterns can be used to provide a metric description of repeated observations of point processes. Due to algorithmic limitations in computing spike-time distance, previous work in determining approximations of the prototype has largely been limited to single dimensional or small data sets. We develop new algorithms for each of these methods that are suitable for larger data sets.

Intracellularly recorded responses of neurons of the motor cortex of awake cats to presentations of Pavlovian conditioned and unconditioned stimuli.

The electrical responses to a conditioned stimulus (click CS) and an unconditioned stimulus (glabella tap US) were studied in single units of the pericruciate cortex of awake cats. There has been no previous direct, in vivo characterization of the intracellular effects in cortical neurons of a CS and US used for associative Pavlovian conditioning. Earlier studies showed that ablation of the pericruciate cortex prevented the development of short latency blink CRs produced by associative pairing of these stimuli.

A glimpse of the brain transforming a sensory signal into a motor response.

Averages were made of neuronal spike activity recorded successively from eight relay regions along the auditorimotor pathway of naive cats and cats conditioned to blink in response to a 70 dB click conditioned stimulus (CS). It was hypothesized that the patterns of activity could be distinguished as sensory or motor by differences in their relationship to the pattern of the acoustic CS vs that of the conditioned response (CR). If so, it was also hypothesized that the acoustic stimulus would be better expressed at early auditorimotor relays and the motor response at later relays along the pathway.