Search PubMedSearch

SEARCH · Search PubMed

Results for “Behavior Control”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

Effects of ethylketazocine and morphine alone and in combination with naloxone on schedule-controlled behavior in pigeons.

The behavioral effects of morphine and ethylketazocine were compared in pigeons responding under multiple fixed-interval, fixed-ratio schedules of food presentation. Both morphine and ethylketazocine produced dose-related decreases in rates of responding maintained under either schedule. Maximal effects of morphine were observed about 15-45 min after injection and typically lasted the entire session (about 60 min). Effects of ethylketazocine had a faster onset (maximal effects were observed within 15 min after injection), and shorter duration (effects diminished within the session). Ethylketazocine and morphine had similar potencies. Dose-effect curves for both drugs were shifted to a similar degree by naloxone.

Analgesics, Opioid

Opioid receptor subtype-specific cross-tolerance to the effects of morphine on schedule-controlled behavior in mice.

Key-press responding of mice was maintained under a fixed-ratio (FR) 30-response schedule of food presentation. Successive 3-min periods during which the experimental chamber was illuminated and the schedule was in effect were preceded by 10-min time-out (TO) periods during which all lights were out and responses had no scheduled consequences. Intraperitoneal (IP) injections of saline or of cumulative doses of drugs were given at the start of each TO period. Successive saline injections had little or no effect on response rates, whereas the mu-opioid agonists morphine (0.1-10.0 mg/kg) and levorphanol (0.1-3.0 mg/kg), the kappa-opioid agonist ethylketazocine (0.03-3.0 mg/kg), the mixed mu-/delta-opioid agonist metkephamid (0.1-10.0 mg/kg), and the nonopioid dissociative anesthetic ketamine (1.0-100.0 mg/kg) generally produced dose-related decreases in response rates. Following chronic administration of morphine (100.0 mg/kg/6 h), tolerance developed to the effects of morphine on rates of responding. In addition, a comparable degree of cross-tolerance developed to the effects of levorphanol and metkephamid. On the other hand, there was no evidence of cross-tolerance to the effects of ethylketazocine or ketamine. These results are consistent with the evidence suggesting that different opioid agonists exert their behavioral effects through distinct classes of opioid receptors.

Animals

The effects of some putative antidepressant agents on the schedule-controlled behavior of the pigeon.

Numerous "second-generation" antidepressants with pharmacological profiles and chemical structures different from those of the tricyclic antidepressants have recently been developed. We examined the actions of four of these compounds (mianserin, maprotiline, trazodone and fluvoxamine) on the responding of pigeons under two different multiple (mult) schedules of grain presentation (a mult fixed-interval (FI) 600-s fixed-ratio (FR) 30-response and a mult FI 200-s FI 200-s in which responding in one component was punished by intermittent presentation of a brief electric shock). The rate of FI 600-s responding was greatly increased by several doses of maprotiline and mianserin, which either did not affect or produced only small increases in the rate of FR 30 responding. Fluvoxamine and trazodone did not produce similar differential effects. Relatively low doses of maprotiline, mianserin and trazodone decreased the FI quarter-lives. Fluvoxamine only decreased the FI quarter-life at a dose that largely eliminated responding. Mianserin produced proportionally greater increases in the rate of punished FI 200-s responding than in the rate of unpunished FI 200-s responding. Selective effects on punished responding were not seen with maprotiline, fluvoxamine and trazodone.

Animals

Tolerance to antinociceptive effects of morphine without tolerance to its effects on schedule-controlled behavior.

The development of tolerance to behavioral effects of morphine was investigated in rats that responded on a two-lever, multiple-trial, multiple differential-reinforcement-of-low-rate fixed-ratio (mult DRL FR) schedule of food presentation. Stable performances were maintained when sessions were conducted just twice per week. The effects of cumulative doses of morphine (1.0-8.0 mg/kg) or chlordiazepoxide (CDP; 4.0-32.0 mg/kg) were evaluated once per week; saline injections were given in the intervening sessions. The effects of saline and morphine on nociception were also evaluated in hot-plate tests conducted on the same subjects 15 min after selected operant sessions. Initially, morphine produced dose-related decreases in response rates and reinforcement rates in the DRL and FR components as well as significant increases in hot-plate response latencies. Following weekly administration of morphine (1.0-8.0 mg/kg) for 10 weeks, there was little or no tolerance to its effects on operant behavior. In contrast, complete tolerance developed to the antinociceptive effects of morphine. These results suggest that tolerance to various behavioral effects of morphine may be dissociated, and that the loss of reinforcement may be insufficient by itself to produce tolerance to effects of morphine on operant behavior. Additionally, whereas CDP initially produced only dose-related decreases in DRL and FR response rates, following weekly morphine the smaller doses of CDP (4.0-16.0 mg/kg) produced increases in response rates.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Effects of chronic d-amphetamine treatment on schedule-controlled behavior.

The effect of d-amphetamine added to the drinking water on the rate of conditioned lever pressing by rats was determined using fixed-ratio 30 (FR-30) and fixed-interval 2-min (FI-2) schedules of food presentation. After 32 days of gradual increase in drug concentration the average drug ingestion was 13 mg/kg/day. In tests with various doses of d-amphetamine injected before and after the chronic ingestion regimen, the rate-decreasing effects of d-amphetamine on FR responding were attenuated after chronic treatment, indicating development of a two- to three-fold tolerance. However, the rate-decreasing effect of d-amphetamine on FI responding was not altered by chronic ingestion. Since acute amphetamine treatment reduced the reinforcement frequency under the FR but not the FI schedule, these results are consistent with the hypothesis that a 'behavioral tolerance' will develop most readily to drug effects that decrease the frequency of reinforcement. Upon removal of d-amphetamine from the drinking water there was some increase in the rate of FR responding, but no change in FI responding.

Animals

Effect of repeated intraperitoneal injections of soman on schedule-controlled behavior in the rat.

Intraperitoneal (IP) administration of the acetylcholinesterase inhibitor, soman (10-40 micrograms/kg), suppressed in a dose-related manner response rates in rats maintained under a multiple fixed-interval 50-s fixed-ratio 25 schedule of food delivery. Chronic administration of soman at weekly intervals resulted in tolerance to the response. When soman administration was separated by 2-5 weeks in individual rats, the suppressive effects of the agent again became apparent. Analysis of acetylcholinesterase activity revealed that enzyme inhibition was limited to gastrointestinal areas near the site of injection. There was no significant effect on brain acetylcholinesterase even following IP injection of doses which completely suppressed responding. The IP route may be useful for studying tolerance and other chronic effects of soman without producing generalized toxicity.

Acetylcholinesterase

Naloxone effects on schedule-controlled behavior in morphine-pelleted rats.

The effects of morphine pellet implantation and naloxone administration were examined in rats lever pressing under inter-response time schedules of food presentation. Subcutaneous implantation of a morphine pellet initially decreased lever-pressing rates. Tolerance to this effect developed within 3--4 days. Naloxone (0.25--1.0 mg/kg) decreased response rates in morphine-pelleted rats in a dose-dependent and time-dependent manner. All doses of naloxone severely decreased rates of lever pressing on days four to nine post-pellet. This rate-decreasing effect persisted 7--17 days for 0.25 mg/kg naloxone, 9--22 days for 0.50 mg/kg, and 13--28 days for 1.0 mg/kg. Decreases in response rate were due to an increased frequency of long pauses and not to marked shifts in the temporal patterning of those lever presses that did occur. Changes in response rate after naloxone were accompanied by body weight loss. Area values summarizing the naloxone-induced changes in response rate or body weight over time after pellet implantation increased as a function of naloxone dose. Naloxone (0.25--1.0 mg/kg) did not alter performance by placebo-pelleted rats.

Animals

Schedule-controlled behavior as an index of the development and loss of ethanol tolerance in the rat.

Twelve male Sprague-Dawley rats, following training on one of two food-motivated operant schedules (Fixed-Ratio 30 or Variable Interval 30 s), were exposed to an escalating regimen of daily ethanol (1.125-3.0 g/kg, IP) administration. This increasing dose regimen continued until the maximally tolerable dose for each subject was reached. Tolerance was then monitored for approximately 6 months by periodic ethanol challenge doses (1.5 g/kg). Dose-effect curves (DECs) were obtained prior to chronic ethanol (DEC1), immediately after ethanol tolerance development (DEC2), and 6 months (DEC3) following termination of ethanol exposure. At DEC1, ethanol produced dose-dependent decreases in rate on both schedules with no significant schedule differences in ED50 (the dose effective at reducing the maximal response rate by one-half) values. Maximal tolerance was achieved in means of 46 and 55 days on the VI and FR schedules, respectively. Differences in rate of tolerance acquisition on the initial dose of the chronic regimen (1.125 g/kg) account for most of the difference in the overall rate of acquisition. Comparison of the ED50 data from DECs 1 and 2 indicated that daily ethanol exposure resulted in a 2-fold decrease in ethanol sensitivity (i.e., tolerance) on both operant schedules. The ED50 data from DECs 1 and 3 demonstrated a 1.7-fold decrease in ethanol potency on DEC3. This duration of tolerance was considerably longer than that generally reported, and possibly related to the extended ethanol exposure and the sensitivity of operant schedules to drug effects.

Animals

Effects of sigma receptor ligands on schedule-controlled behavior of rats: relation to sigma and PCP receptor binding affinity.

Eleven drugs were examined for their ability to inhibit sigma and phencyclidine (PCP) receptor binding, as labelled by (+)[3H]-R-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine ((+)-3-PPP), [3H]ditolylguanidine (DTG), (+)[3H]N-allylnormetazocine (NANM) and [3H]1-(1-(2-thienyl)cyclohexyl)piperidine (TCP), in membrane preparations from whole rat brain. The same drugs were studied for their effects under a fixed-ratio (FR) schedule of food reinforcement in rats. The relative potency order of the drugs for decreasing FR responding was: haloperidol greater than (+)-3-PPP greater than (-)NANM greater than BMY 14802 greater than PCP greater than (+)NANM greater than DTG greater than rimcazole greater than JO 1783 greater than JO1784 greater than (-)butaclamol. The binding affinities of all 11 drugs for either the [3H]DTG, (+)[3H]-3-PPP, (+)[3H]NANM or [3H]TCP site did not correlate significantly with the potencies of the same drugs for decreasing FR behavior. Rimcazole, (+)-3-PPP and haloperidol, at behaviorally inactive doses, were studied for their effects as antagonists of the rate-decreasing effects of JO 1784, DTG and (+)NANM: rimcazole attenuated the effects of DTG and (+)NANM but not JO 1784; (+)-3-PPP attenuated the effects of (+)NANM but not JO 1784 and DTG; and haloperidol was devoid of antagonistic actions. Moreover, BMY 14802 did not attenuate the rate-decreasing effects of (+)-3-PPP. These results further indicate that it is difficult to distinguish between purported sigma agonist and antagonist drugs.

Animals

Effects of MK-801 stereoisomers on schedule-controlled behavior in rats.

Behavioral effects of (+)MK-801 (0.03-0.32 mg/kg) and (-)MK-801 (0.32-3.20 mg/kg) were evaluated in rats using a multiple fixed-ratio, fixed-interval (FR20, FI2) schedule of food presentation. Both enantiomers produced dose-dependent decreases in response rate under the FR20 and in this respect (+)MK-801 was approximately ten times as potent as (-)MK-801. Under the FI2 schedule component, the (+) enantiomer produced substantial increases as well as decreases in response rate whereas the (-) enantiomer produced only decreases. When 0.178 mg/kg (+)MK-801 and 1.78 mg/kg (-)MK-801 were administered for 11 consecutive days, tolerance developed to the decrease in response rate under the FR20 schedule component. Tolerance to the effects of the (+) enantiomer under the FI2 schedule component was indicated by progressively larger increases in response rate than those observed during acute administration. These results support potential therapeutic applications of MK-801.

Animals

Single cell activity in the auditory cortex of the unanesthetized, behaving monkey: correlation with stimulus controlled behavior.

The neural activity of 60 cells in the auditory cortices of two rhesus monkeys was examined in relation to systematic variations in cued reinforcement conditions. Subjects were trained on a variant of the auditory reaction time (RT) task. In the final behavioral paradigm monkeys were rewarded for rapid key releases to all tonal stimuli in one reinforcement condition (frequency irrelevant = FI), while in the other stimulus-cued condition (frequency discrimination = FD) releases to certain tonal test frequencies were unrewarded. Upon completion of behavioral training, RTs to identical tonal test stimuli were longer and more variable when presented in the unrewarded (FD) condition. Following neurosurgery it was possible to observe the effects of reinforcement condition on auditory RT performance and the activity of single auditory cortical cells simultaneously. Of the auditory cortical cells sampled, 25% showed definite and repeatable alterations in evoked activity to the same tonal stimulus which were correlated with reinforcement condition. For nearly all cells examined the influence of reinforcement condition was much the same: on excitatory responses were increased in the FD condition. A few of the cells also showed alterations in latency and/or pattern of evoked discharge. Importantly, none of the units examined showed changes in their spontaneous discharge rates as a function of reinforcement condition. both peripheral mechanical and central neural theories were considered as a basis for the observed neural alterations. The specificity and latency of the alterations as well as the absence of tonic effects seemed to indicate that the neural changes observed were mediated by central mechanisms. Our results strongly suggest that the activity of a sample of auditory cortical neurons depends on the behavioral state of the preparation. We propose that 'behavioral state", appropriately defined, can be a useful concept for neurophysiologists.

Action Potentials