Clozapine and prazosin slow the rhythm of head movements during focused stereotypy induced by d-amphetamine in rats

Abstract

The results show that clozapine diminished the rhythm and vigor of d-amphetamine-induced stereotyped head movements but, at the same time, lengthened the duration of the expression of the stereotypy. alpha1 antagonism is a likely contributor to the rhythm-modulating effects of clozapine.

Apomorphine enhances harmaline-induced tremor in rats

“…The concept and applications of this instrument for measurement of tremor, locomotor activity and stereotypy in rodents were described in the USA and pending international patents (USA Patent no. 6,601,010), as well as in published research [24][25][26][27][28][29].…”

“…Focused stereotypy ''was defined by a quantitative score that combined a direct instrumental measure of spacial confinement with the variance in the vertical force oscillations, that the rat exhibited within that space'' [27][28][29]. This parameter aimed to reflect repetitive head movements of frequency between 6.5 (7.5) and 12 Hz induced by dopaminomimetics in ''one-place'' [27,29] However, this parameter did not differentiate between various forms of stereotypy (e.g., sniffing, licking, gnawing, biting). The plate was divided into a 16 by 16 grid of 256 squares to calculate the percentage of time and the force variance while the animal was in each square.…”

“…The percentage of time spent in each square was multiplied by the force variance for that square and divided by the total number of squares occupied. This value was then summed for all 256 squares to obtain the focused stereotypy score for six 15-frame series [27][28][29]. A total of 80 rats were used for the experiments; however, one rat treated with apomorphine (0.5 mg/kg) and harmaline (15 mg/ kg) was discarded due to a recording error.…”

Exercise as a Potential Treatment for Drug Abuse: Evidence from Preclinical Studies

“…These episodes of excessive drug intake can be modeled in the laboratory by giving subjects unlimited-access to a drug during 12- to 24-h test sessions. During these sessions, animals will exhibit high levels of drug intake that are associated with a loss of circadian patterns of motor activity, a dysregulation of homeostatic autonomic functions, and acute withdrawal symptoms upon session termination (Mutschler and Miczek, 1998; Tornatzky and Miczek, 2000; Fowler et al, 2007). Recently, Smith et al (2011b) reported that exercise reduces cocaine intake during a 23-h period of unlimited drug access.…”

Central administration of p-hydroxyamphetamine produces a behavioral stimulant effect in rodents: evidence for the involvement of dopaminergic systems

“…In rodents, it has been reported that administration of drugs of abuse, including AMPH and METH, induces multiple behavioral responses, such as increased locomotor activity (Porrino et al 1984;Salahpour et al 2008), stereotypy (Battisti et al 2000;Fowler et al 2007), and disrupted prepulse inhibition of acoustic response (Sills 1999;Peleg-Raibstein et al 2008). p-Hydroxyamphetamine (p-OHA), an AMPH and METH metabolite, has been shown to have a number of pharmacological actions, including causing abnormal behaviors such as those induced by drugs of abuse (Simpson 1980;Dougan et al 1986;Arai et al 1990; Kaminskas et al 2002).…”