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Biomedical subjects

T Palfai

Publications and source records attributed to T Palfai.

At least 19 recordsLinked to original sources
PubMed1992

Housing influences exploration and social interaction of control and DSP-4-treated rats.

Exploratory behavior and social interaction were investigated in rats that were reared in different social environments following neonatal injection with either water vehicle or the norepinephrine neurotoxin, DSP-4. At weaning, they were placed in a familiar or novel bedding type and were housed in either vehicle control-only, DSP-4-only, or mixed vehicle control and DSP-4 groups for 10 days. They were then observed in three different situations: the home cage, the cage of an unfamiliar rat, and an open field. Compared to rats housed in vehicle control-only or DSP-4-only groups, rats housed in mixed DSP-4 and vehicle control groups showed elevated exploration behavior in the home cage. Also, rats housed in mixed groups in the familiar bedding, but not the novel one, showed abnormally low levels of rearing in an open field test and reduced social interaction with unfamiliar rats. The implications of these results for a new animal model of anxiety are discussed.

Adrenergic Agents↗
PubMed1990

Impaired hoarding and olfactory learning in DSP-4-treated rats and control cagemates.

The possibility that variables affecting rats' home-cage odor preferences also influence hoarding behavior was examined. Neonatal male rats were injected SC with the noradrenergic neurotoxin, N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4), or with vehicle. At weaning, rats were assigned to control-only, DSP-4-only, or mixed groups of DSP-4 and control rats. For the next 10 days, half the rats in each social condition were housed in cedar shavings, and remaining rats were housed in pine. Exposure to cedar significantly increased preference for the odor in control-only groups, but not in DSP-4-only or mixed treatment groups. Control-only groups also hoarded significantly more pellets per animal than rats in the other two social conditions. The results suggest that both olfactory adaptation and hoarding can be impaired by either neonatal NE depletion or an abnormal social environment.

Animals↗
PubMed1986

Effects of amnesic doses of reserpine or syrosingopine on mouse brain acetylcholine levels.

The effects of reserpine and syrosingopine on mouse whole brain acetylcholine levels were examined. At 2 or 24 hr following injection, the brains were removed and analyzed by mass spectrometry. No differences were found between drug-treated and control mice in the acetylcholine content of the brain at either time interval. The results suggest that whole brain acetylcholine levels do not predict the amnesic effects of either reserpine or syrosingopine.

Acetylcholine↗
PubMed1984

Effect of l-dopa or bromocriptine on feeding and motor behavior of rats with lesions in the globus pallidus.

Rats were lesioned bilaterally in the globus pallidus (GP) with anodal current or 6-OHDA, and were observed in various motor tests 10 min daily for 3 weeks. Body weight, home cage water and food intakes were recorded daily under two different food accessibility conditions. The lesions produced adipsia, aphagia, loss of body weight and motor impairments which could not be reversed by either l-dopa or bromocriptine. Animals could be made to recover, however, by making food easily accessible and palatable. The results do not support a "metabolic" role for the GP but support the idea that aphagia, adipsia and mortality is due to motoric impairments produced by the lesion.

Animals↗
PubMed1983

The effect of reserpine, syrosingopine, and guanethidine on the retention of discriminated escape reversal: peripherally administered catecholamines cannot reverse the reserpine amnesia in this situation.

In a series of experiments, the effects of reserpine, syrosingopine, and guanethidine on retention of a discriminated escape reversal training were investigated in mice. The peripherally and centrally acting reserpine produced amnesia while the primarily peripherally acting compounds, syrosingopine or guanethidine, did not produce amnesia even when given in high dosages or when training was given with low footshock. Unlike in the passive avoidance situation, peripherally administered norepinephrine or dopamine was not able to attenuate the reserpine-induced amnesia. The results were discussed in terms of the role of biogenic amines in memory formation.

Animals↗
PubMed1982

Effect of age, clonidine or propranolol on behavioral toxicity induced with digitoxin in mice.

In three experiments, behavioral toxicity induced by 5 different dose levels of digitoxin was investigated in mice that were treated with either clonidine or propranolol or were either young (70-140 days), middle aged (240-260) or old (450-600). Observed on four drug-induced behavior categories, it was found that both clonidine and propranolol attenuated the toxic effects of relatively low dose levels of digitoxin, while at higher digitoxin dose levels only propranolol was able to reduce significantly the ED50 and the LD50. The results were discussed in terms of adrenergic mechanisms mediating digitoxin toxicity. Aged mice were found to be the least and middle aged the most resistant to the toxic effects of digitoxin.

Aging↗
PubMed1981

Reversal of guanethidine- and diethyldithiocarbamate-induced amnesia by peripherally-administered catecholamines.

The effect of peripherally-administered catecholamines on guanethidine- and diethyldithiocarbamate-induced amnesia of a PA training in mice was investigated. The amnesic effect of guanethidine could be blocked with 50 mg/kg DA, or 0.75 mg/kg NE when given either before, immediately, or 10 min after but not 90 min following PA. Epinephrine or a lower dose of DA could be attenuate the guanethidine-induced amnesia. The amnesic effect of diethyldithiocarbamate could be blocked with 50 mg/kg DA, 0.75 mg/kg NE or 0.5 mg/kg E when given either before, immediately or 10 ming after but not 90 min following PA. The amnesic effects of these compounds were interpreted in terms of their peripheral antiadrenergic actions.

Animals↗
PubMed1980

Comparisons of the effects of guanethidine, 6-hydroxydopamine and diethyldithiocarbamate on retention of passive avoidance.

Depending on the dose levels, guanethidine and diethyldithiocarbamate produced time dependent amnesia for a one-trial passive avoidance task. 6-Hydroxydopamine given at any dose level or at any time interval before or after training did not result in retention deficits. The results were discussed in terms of the effects of these agents on peripheral biogenic amines and the possible role of these amines in memory formation.

Animals↗
PubMed1979

Comparison of the long-term cumulative effects of reserpine and syrosingopine on general activity.

Reserpine, but not syrosingopine, produced a cumulative decrease in general motor activity when administered once every 10 days for a total of 8 drug treatments. The maximum depression of activity was evident following the second reserpine administration. Following a 30 day drug-free period animals previously treated with reserpine still exhibited decreased motor activity. The data suggest that chronic reserpine treatment may result in long term, and perhaps permanent behavioral effects.

Animals↗
PubMed1979

Peripheral catecholamines and memory: characteristics of syrosingopine-induced amnesia.

The effect of syrosingopine on retention of a passive avoidance trial in mice was investigated. The drug given in doses of 2.5, 4.0 or 6.0 mg/kg 2 hr before training, but not when given 24 or 0.5 hr or immediately after training, resulted in amnesia 7 days later. Dopamine or norepinephrine administered systemically 15 min before to 10 min after training was able to block the syrosingopine-induced amnesia. The role of peripheral catecholamines in memory formation was discussed.

Amnesia↗
PubMed1979

Memory storage impairment or retrieval failure: pharmacologically distinguishable processes.

The effects of reserpine and syrosingopine on retention of a passive avoidance task in mice were investigated. Following repeated exposure to the training apparatus, the amnesia induced with syrosingopine could be reversed, the amnesia induced with reserpine could not. The amnesia produced by these agents was still evident 35 days following training. The results were discussed in terms of the effects of these drugs on memory consolidation and/or retrieval.

Animals↗
PubMed1978

Catecholamine levels in the whole brain and the probability of memory formation are not related.

Amnesia was induced with reserpine or was blocked with 1-dopa and 5-hydroxytrptophan before or after passive avoidance training in mice. The levels of dopamine and norepinephrine in the whole brain were measured in corresponding groups with gas chromatography-mass spectrometry. No correlation was found between retention and the levels of these catecholamines in the brain.

5-Hydroxytryptophan↗
PubMed1978

Time-dependent effects of reserpine on retention of passive avoidance.

Reserpine produced amnesia for a one-trial passive avoidance task when given 2, 3, 4, 5 hr before but not when given 1, 8, 12, 24 hr or 30 min before, immediately, 90 min or 2, 4, 5, 6, 8, 9, 12, 24 hr following training. The results were discussed in terms of the reserpine effect on biogenic amines and their possible role in memory formation.

Animals↗
PubMed1977

Food deprivation-induced alcohol ingestion in the mouse: calories versus primary sensory preference.

Random bred Swiss mice showed preference for water over 10% ethanol solution when unlimited food was available. When partially food deprived, the preference was reversed in 5 out of 8 animals. About half of the naive mice, however, ingested substantial amounts of this ethanol solution at the very first exposure when partially food deprived for 12 days. It is suggested that while the caloric value of ethanol is reinforcing, food deprivation might make the sensory effects of ethanol also reinforcing.

Alcohol Drinking↗
PubMed1977

Effects of reserpine on retention of escape reversal in mice: absence of state-dependent learning.

A discriminated escape training paradigm was used to study the effects of reserpine on learning and memory in mice. Intraperitoneal injection of reserpine before reversal training had no effect on acquisition but did produced a time-and dose-dependent impairment of retention test performance 10 days later. These results suggested that reserpine may have interfered with some aspect of memory storage. Retention impairments observed when a 2.0 mg/kg reserpine injection was given 2 hr before reversal training were not attenuated by readministering the drug before testing, a finding that provides no support for a state-dependency interpretation. Furthermore, animals treated with reserpine exhibited inferior retention of previous training, regardless of the pharmacological state present during that learning. This was interpreted as a drug-induced impairment of memory retrieval. In addition, performance during the initial discriminated escape training session suggested that reserpine may also impair acquisition under some conditions. In the last experiment, it was found that when the catecholamine precursor L-dihydroxyphenylalamine (100 mg/kg) and the indole amine precursor D,L-5-hydroxytryptophan (125 mg/kg) were both given after reserpine treatment, subsequent retention performance was not significantly impaired. The results are discussed in terms of the possible roles of biogenic amines in arousal, learning, and memory.

5-Hydroxytryptophan↗
PubMed1976

Pentylenetetrazol-induced amnesia: a case for overt seizures.

In this study, the possible role of overt convulsions following pentylenetetrazol (PTZ) in retrograde amnesia was investigated. Following a single passive avoidance conditioning, when overt convulsions were blocked with sodium pentobarbital (Nem), the amnesic effect of pentylenetetrazol was also blocked. Subconvulsive doses of the drug did not produce amnesia. Animals that received a typically convulsive dose of the drug but failed to convulse were not amnesic; only animals with overt convulsions were different from saline controls. The data suggest that overt convulsions may be necessary for the development of pentylenetetrazol-induced retrograde amnesia.

Amnesia↗