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M Laska

Publications and source records attributed to M Laska.

45 records · Page 3Linked to original sources
PubMed1993

Assessing olfactory performance in a New World primate, Saimiri sciureus.

Using a task designed to simulate olfactory-guided foraging behavior, this study demonstrates for the first time that olfactory performance can be reliably assessed in squirrel monkeys. Small flip-top vials were fixed in random order to the arms of a climbing frame and equipped with odorized strips signalling either that they contained a peanut food reward (S+) or that they did not (S-), and three adult female monkeys were allowed 1 min to harvest as many baited nuts from this tree as possible. Given five 1-min trials per day, animals took between 15 and 25 days to reach the criterion of 80% correct choices, could readily transfer to new S+ or S- stimuli, and could remember the task even after a 1-month break. The precision and consistency of the monkeys' performance in tests of discrimination ability and sensitivity demonstrate the suitability of this paradigm for assessing olfactory function, and a first test of human subjects using the same cups and odorants showed that it may also be used to directly compare olfactory performance in human and nonhuman primates.

Adult↗
PubMed1992

Maturation of binaural interaction components in auditory brainstem responses of young guinea pigs with monaural or binaural conductive hearing loss.

Reversible conductive hearing loss created during the first 4 weeks post partum caused marked alterations in the maturation of binaural interaction components in the auditory brainstem responses of guinea pigs. In untreated control animals all three components investigated demonstrated postnatal development in terms of latency shortening that was completed during the first 3 weeks of life. Plugging of both external ear canals caused a significant delay in the maturation of the late component DN2, where latency values of the controls were reached only 2 weeks after the end of the treatment, i.e. after 6 weeks of life. Monaural deprivation likewise led to a retarded development of peak latencies during the phase of imbalanced sensory input. After the end of the one-sided conductive hearing loss the maturation process was markedly enhanced, even resulting in latency values for DN2 and DP1 that were significantly shorter than those of the controls. This phenomenon persisted until the end of the study period and was the case for both plugged and untreated ears in this group of animals. The time course of latencies in two other groups of experimental animals which were deprived in the same way as adults suggests that the effects observed are due to a sensitive period in the maturation process of the auditory pathway.

Age Factors↗
PubMed1989

[Effect of binaural conductive hearing loss on maturation of acoustically evoked potentials (auditory brain stem response, middle latency response) in guinea pigs].

During the early development of the acoustic system a conductive hearing loss may alter the maturation of acoustically evoked potentials and affect the development of hearing. The present experiments were carried out in newborn guinea pigs with binaural conductive hearing loss. The external ear canals were plugged over a period of one month from the first day postpartum. During and after deprivation click-evoked Auditory Brainstem Responses (ABR) and Middle Latency Responses (MLR) were collected to analyze changes in the maturation of these potentials in comparison to untreated animals. This type of deprivation is characterized by threshold elevations of about 40 dB over a wide frequency range. In young deprived animals, ABR Latencies (PIII, PV) and interpeak latencies exhibited a significant delay with a maximum between day 13 and 19, which disappeared within 10 days after the end of the treatment. MLR latencies were also significantly affected after three to four weeks of the deprivation phase. In contrast to the ABR, the recovery of the latencies was completed within four to six weeks. These results therefore indicate that a conductive hearing loss may alter the maturation of the acoustically evoked responses in the sensitive phase after birth. This type of partial deprivation may affect the development of hearing and speech perception in children with chronically occurring otitis media.

Age Factors↗
PubMedDate not supplied

Food avoidance learning in squirrel monkeys and common marmosets.

Using a conditioned food avoidance learning paradigm, six squirrel monkeys (Saimiri sciureus) and six common marmosets (Callithrix jacchus) were tested for their ability to (1) reliably form associations between visual or olfactory cues of a potential food and its palatability and (2) remember such associations over prolonged periods of time. We found (1) that at the group level both species showed one-trial learning with the visual cues color and shape, whereas only the marmosets were able to do so with the olfactory cue, (2) that all individuals from both species learned to reliably avoid the unpalatable food items within 10 trials, (3) a tendency in both species for quicker acquisition of the association with the visual cues compared with the olfactory cue, (4) a tendency for quicker acquisition and higher reliability of the aversion by the marmosets compared with the squirrel monkeys, and (5) that all individuals from both species were able to reliably remember the significance of the visual cues, color and shape, even after 4 months, whereas only the marmosets showed retention of the significance of the olfactory cues for up to 4 weeks. Furthermore, the results suggest that in both species tested, illness is not a necessary prerequisite for food avoidance learning but that the presumably innate rejection responses toward highly concentrated but nontoxic bitter and sour tastants are sufficient to induce robust learning and retention.

Animals↗