Schedules ratio

Andrews. J.S., and Holtzman, S.G. The interaction of ti-amphetamine and naloxone differs for rats trained on separate fixed-interval or fixed-ratio schedules of reinforcement. Pharmacol Biochem Behav 26 167-171, 1987. Angrist, B.M., and Gershon, S. Amphetamine abuse in New York City, 1966-1968. Semin Psychiatry 1 195-207, 1969. 

Monkey (Rhesus) 7-8 yr 1 x/d (C) 1.5 (altered performance on a fixed-interval-fixed-ratio schedule of reinforcement at age 7-8 years) Rice 1992 PbAc... 

Ranaldi, R., Wise, R.A. Intravenous self-administration of methamphetamine-heroin (speedball) combinations under a progressive-ratio schedule of reinforcement in rats. Neuroreport. 11 2621, 2000. 

Richardson N., Roberts D. Fluoxetine pre-treatment reduced breaking points on a progressive ratio schedule reinforced by intravenous cocaine administration in the rat. Life Sci. 49 833, 1991. 

Bupropion at low doses (10-30 mg kg ) had no effect on increased intravenous self-administration of nicotine, whereas higher dose of bupropion (30-78 mg kg ) decreased nicotine self-administration under a fixed-ratio schedule. Bupropion (20-40 mg kg ) had no effect on intravenous self-administration of nicotine under a progressive-ratio schedule. 

Rimonabant decreased intravenous self-administration of nicotine under a fixed-ratio schedule decreased responding maintained by nicotine-associated stimuh and blocked nicotine-induced conditioned place preference in rats. 

LeSage MG, Burroughs D, Pentel PR (2006) Effects of nicotine withdrawal on performance under a progressive-ratio schedule of sucrose pellet delivery in rats. Pharmacol Biochem Behav 83 585-591... 

Another indicator of the reinforcing effectiveness of a test substance can be the amount of work an animal will perform to obtain the test substance. This can be investigated with a progressive ratio schedule whereby the response requirement increases for every infusion (Solinas et al. 2004) or after a fixed period of time (Wilcox et al. 2000) until the animal ceases to lever-press for a pre-determined interval,... 

In the habit modality, response is mainly controlled by stimuli that precede rather than follow it (outcomes) (Dickinson, 1994). As a result of this, devaluation of response outcome fails to impair habit responding. Habit responding takes place as a result of exhaustive training on high ratio schedules or under variable interval schedules where reinforcement is loosely related to response (Dickinson, 1994). 

Evidence for a role of NAc DA in cocaine reinforcement has been provided by studies of the effect of 6-OHDA lesions on cocaine self-administration. Thus, 6-OHDA lesions of the DA innervation of the nucleus accumbens result in extinction-like effects on responding for cocaine in FR schedules (Roberts et al., 1977 Roberts et al., 1980, Pettit et al., 1984) and in a decrease in break point in progressive ratio schedules (Koob et al.,... 

Griffiths RR, Bradford LD, Brady JV (1979) Progressive ratio and fixed ratio schedules of cocaine-maintained responding in baboons. Psychopharmacol 65 125-136. 

Mendrek A, Blaha CD, Phillips AG (1998) Pre-exposure of rats to amphetamine sensitizes self-administration of this drug under a progressive ratio schedule. Psychopharmacology 735(4) 416-422. 

Roberts DCS, Loh EA, Vickers G (1989) Self-administration of cocaine on a progressive ratio schedule in rats dose-response relationship and effect of haloperidol pretreatment. Psychopharmacology 97 535-538. 

Fixed ratio schedule delivers reinforcement after a fixed number of responses... 

Solinas M, Panlilio LV, Antoniou K, Pappas LA, Goldberg SR. The cannabinoid CB 1 antagonist N-piperidinyl-5-(4-chlorophenyl)-l-(2,4-dichlorophenyl)-4-methylpyrazole-3-carboxamide (SR-141716A) differentially alters the reinforcing effects of heroin under continuous reinforcement, fixed ratio, and progressive ratio schedules of drug self-administration in rats. J. Pharmacol. Exp. Ther. 306, 93-102 (2003). 

Richardson N, Roberts D (1996) Progressive ratio schedules in drug self-administration studies in rats a method to evaluate reinforcing efficacy. J Neurosci Methods 66 1-11. 

Fixed ratio schedule Altered Padich and Zenick, 1977... 

One approach is to find a means to reinforce the desired behaviour, preferably on a variable ratio schedule. One such example was reported from a factory in Liverpool (see Chapter 3). The introduction of a prize draw, based upon tokens collected for attendance, led to the reduction of absenteeism levels to almost zero. Other schemes have used cash bonuses for those attending on days chosen at random during the month. Both of these types of schemes use variable ratio reinforcement - one by means of a draw, the other by the random choice of the day on which attendance is rewarded. (It is worth noting that both also required attendance at the required starting time, thus also reinforcing punctuality.)... 

Roberts DCS, Bennett SAL (1993) Heroin self-administration in rats under a progressive ratio schedule of reinforcement. Psychopharmacology 111 215-218 Shelton KL (2007) Inhaled toluene vapor as a discriminative stimulus. Behav Pharmacol 18 219-229... 

Male weanling Long—Evans rats Drinking water Pb at 1 50 ppm fixed-ratio schedules PbB, 26 pg/dl Increased response rates and shorter waiting times with Pb exposure. Effects reversed by quinpirole Brockel and Cory-Slechta (1998)... 

Before closing this discussion of simple reinforcement schedules we wish to make a brief comment on the ratio schedules. 

One caution in using ratio schedules to evaluate foods might be noted. On ratio schedules the individual responses tend to become "chained" together so that performance of any one response is determined by performance of the immediately preceding response. Consequently, the rate of response on the ratio schedules may not be a sensitive indicator of the value of a reinforcer. However, other measures of performance reflect a rein-... 

---