Conditioned taste aversion in Philippine rice rats (R. r. mindanensis): Comparisons among drugs, dosages, modes of administration, and sexes

Hallock²,

Kennedy³

2003

Two experiments suggested that the temporal pattern of a taste response in the brain can convey meaningful information. In Experiment 1, rats avoided lick-contingent electrical stimulation of the nucleus of the solitary tract (NTS; the first synaptic relay for taste) when the temporal pattern of pulses mimicked the electrophysiological response to quinine, but not when the temporal pattern was randomized. In Experiment 2, rats avoided lick-contingent electrical stimulation of the NTS that mimicked the temporal pattern of a sucrose response following stimulation-illness pairings. This aversion generalized to sucrose but not to the other tastants; extinction of the aversion to electrical stimulation also extinguished the aversion to sucrose. Results replicate and extend previous findings (P. M. Di Lorenzo & G. S. Hecht, 1993).

Section: Methodsmentioning

confidence: 99%

Temporal Coding of Sensation: Mimicking Taste Quality With Electrical Stimulation of the Brain.

Hallock²,

Kennedy³

2003

“…Immediately after the stimulation session, animals in the NTS-LiCl group ( n = 7) were given an intraperitoneal injection of LiCl (0.3 M, 1% body weight). This dosage of LiCl was used to ensure the rapid acquisition of an aversion (Nachman & Ashe, 1973; Shumake, Sterner, Gaddis, & Crane, 1982). Training sessions were given every 3rd day until the number of licks fell below 200.…”

Section: Methodsmentioning

confidence: 99%

Perceptual consequences of electrical stimulation in the gustatory system.

Hecht²

1993

To investigate the role of temporal coding in the neural processing of taste, trains of electrical pulses of varying frequency were delivered to the nucleus of the solitary tract (NTS) in awake rats. The temporal patterns of these trains mimicked the temporal patterns of electrophysiological responses of single neurons to natural tastes. In Experiment 1, water-deprived rats were first trained to lick water in an experimental chamber. On training days, licking water produced a sucroselike electrical pulse train in the NTS. At the end of these sessions, experimental animals were made ill by an injection of LiCl and subsequently learned to avoid licking when LiCl was paired with NTS stimulation. In Experiment 2, rats refused to lick water when licking produced a quininelike pattern of NTS stimulation but licked enthusiastically when licking produced a pattern of NTS stimulation similar to the natural response to sucrose.

“…Immediately after the training session, all rats in these groups were given an injection of LiCl (0.3 M ip, 1% body weight). We used this dosage of LiCl to ensure the rapid acquisition of an aversion (Nachman & Ashe, 1973; Shumake, Sterner, Gaddis, & Crane, 1982). Training sessions were given every other day; water without stimulation was presented on the intervening days.…”

Section: General Methodsmentioning

confidence: 99%

Making time count: Functional evidence for temporal coding of taste sensation.

Leshchinskiy

Moroney

et al. 2009

Although the temporal characteristics of neural responses have been proposed as a mechanism for sensory neural coding, there has been little evidence thus far that this type of information is actually used by the nervous system. Here the authors show that patterned electrical pulses trains that mimic the response to the taste of quinine can produce a bitterlike sensation when delivered to the nucleus tractus solitarius of behaving rats. Following conditioned aversion training using either “quinine simulation” patterns of electrical stimulation or natural quinine (0.1 mM) as a conditioned stimulus, rats specifically generalized the aversion to 2 bitter tastants: quinine and urea. Randomization of the quinine simulation patterns resulted in generalization patterns that resembled those to a perithreshold concentration (0.01 mM) of quinine. These data provide strong evidence that the temporal pattern of brainstem activity may convey information about taste quality and underscore the functional significance of temporal coding.