Effects of nicotine on motor co-ordination and spontaneous activity in mice

Doses of nicotine (0·2 and 0·4 mg/kg subcutaneously) which depress spontaneous activity, improve the ability of mice to remain on a rotating rod, indicating that the reduction in activity is not due to non-specific disruption of motor ability.

The performance of rats trained to press a bar for water rewards is stimulated by small subcutaneous doses (0·05, 0·1 mg/kg) of nicotine; larger doses (0·2, 0·4 mg/kg) briefly reduce the rate of bar-pressing before increasing it (Morrison, 1967). The larger doses also depress spontaneous motor activity in mice (Morrison & Armitage, 1967). In the present experiments a rotating rod (Dunham & Miya, 1957) was used to test whether the depresssion of spontaneous activity caused by nicotine is a result of motor incapacity.

Reserpine and the partial reinforcement effect in the fish Tilapia H. macrocephala

A strong partial reinforcement effect was produced in 20 fish trained to a free operant striking response by injection of reserpine before extinction of the response. This was interpreted as a result of inhibition of responding during extinction of 20 Ss trained on a consistent schedule of reinforcement rather than facilitation of responding in Ss trained on a .4 variable ratio schedule of reinforcement.

Methedrine as an adjunct to conditioning treatment of nocturnal enuresis in normal and institutionalized retarded subjects

A replication of the finding that entireties who are given Methedrine as an adjunct to conditioning treatment display more rapid conditioning was attempted with both normal and retarded Ss. The drug failed to enhance conditioning in either normal or retarded Ss. Success figures of 70% for normal Ss and 50% for retarded Ss were found.

Joint effect of amobarbital and response prevention of CAR extinction

The purpose of this study was to extend previous findings of enhanced CAR extinction with response prevention by demonstrating that extinction may be further facilitated by amobarbital treatment during response prevention. Ss administered amobarbital during CAR prevention did not differ significantly from the control Ss in extinction performance. Extinction was not facilitated by amobarbital when administered during CAR prevention.

A comparison of the punishing effects of response-produced shock and response-produced time out

Electric shock and time out were compared as punishers in the squirrel monkey. At the parameters investigated, both suppressed responding to about the same degree. Scheduling punishment intermittently or administering pentobarbital reduced the effectiveness of both punishers. The effects of the punishers were different in that responding suppressed by shock recovered more within a session than responding suppressed by time out. Responding was suppressed after some shock-punishment components, but less often after time-out-punishment components. The similarities of the two punishers were more striking than the differences.

The mechanism of the tranquillizing action of asarone from Acorus calamus Linn

Asarone, the active principle of the indigenous Indian plant Acorus calamus Linn., did not cause any change in the noradrenaline content of whole brain of rats. Unlike tetrabenazine, pretreatment with asarone failed to block the effect of reserpine on the spontaneous motor activity and ptosis of mice, as well as the conditioned avoidance response of trained rats. These findings show that, though in chemical structure asarone resembles a part of the reserpine molecule, its mechanism of action is different from this drug. In animals in which brain noradrenaline has been lowered by pretreatment with α-methyl-l-tyrosine, the effects of asarone, namely, hypothermia, potentiation of barbiturate hypnosis and specific blockade of conditioned avoidance response, were found to be markedly enhanced. It seems that the sedative effect of asarone is dependent on the depression of the ergotropic division of the hypothalamus.

Effect of LSD-25 in the rat on operant approach to a visual or auditory conditioned stimulus

Albino rats ( N = 200) required progressively more time per trial to perform a previously learned response to obtain food reward than saline and untreated controls following administration of increasing doses of LSD-25 (100, 200, 400 μg/kg). Ss conditioned to respond to a light stimulus showed more response decrement than animals cued by an auditory stimulus for increasing LSD-25 levels. Within each stimulus modality, a greater response decrement was observed following administration of LSD-25 for the higher intensity stimulus value for all but one treatment group. Results were discussed in relation to reports of sensitization and sensory blockage actions for LSD-25.