Radial maze

FIGURE 10 Effect of bethanechol on memory in lesioned rats. Be-thanechol was released from PCPP-SA 50 50 implanted intracerebrally in rats. The effect of the bethanechol released on the performance of lesioned rats in a radial maze test was performed as described in the text. 

In a radial maze a number of arms of equal length radiate from a central point, where the animal is placed. Initially food is placed at the end of each arm and the rat is expected to learn that fact by exploring and entering each arm. The test of memory is to see whether on re-exposure to the maze the rat remembers only to enter an arm not previously visited and so still containing food. 

Snakes were trained to look for earthworm bits in a plastic 5-arm radial maze (similar to that used by Kubie and Halpern 1978,1979). At the beginning of every trial, the snake was placed in an open-ended cylinder placed in the center of the foraging apparatus. After 1 minute, the cylinder was lifted and the snake was allowed to explore the apparatus. During training, the goal box at the end of each arm of the maze was baited with earthworm bits to encourage the animal to enter each arm in search of food. Tongue-flick data was recorded before and after prey consumption. 

Passive avoidance task Morris water maze radial maze operant behavior tasks... 

Olton, D.S., The radial maze as a tool in behavioural pharmacology, Physiol. Behav., 40, 793-797, 1986. 

Ginseng extract improves the spatial learning performance of aged rats in an eight-arm radial maze and operant discrimination task (Nitta et al. 1995). It also improves memory performance in active-avoidance (shuttle-box) and passive-avoidance (step-down) tasks, and reinforces staircase-maze learning in both young and aged rats. (Petkov and Mosharrof 1987 Petkov et al. 1990 Petkov et al. 1992). The effects were also very dose dependent, with inverted U-shape dose-response curves. 

Nitta H, Matsumoto K, Shimizu M, Ni XH, Watanabe H. (1995). Panax ginseng extract improves the performance of aged Fischer 344 rats in radial maze task but not in operant brightness discrimination task. Biol Pharm Bull. 18(9) 1286-88. 

Heisley S, Fiorella D, Rabin RA, Winter JC. (1997a). Effects of ibogaine on performance in the 8-arm radial maze. Pharmacol Biochem Behav. 58(1) 37-41. 

Similarly, intrahippocampal injections of 8-OH-DPAT induced no change in performance levels of the rat trained to run in a radial maze (Buhot et al. 1995). However, the intrahippocampal injection of the 5-HTjg receptor agonist CP-93,129 [3-(l,2,5,6-tetrahydropyrid-4-yl] pyrrolo [3,2-6] pyrid-5-one] induced a higher frequency of reference memory errors than of working memory. It was concluded that stimulation of 5-HT,g receptors in the CAl field of the dorsal hippocampus impairs performance of rats in a spatial learning task. 

The role of other forebrain sites in the mediation of 5-HTj, receptor-induced changes in cognition remains to be investigated, and the establishment of dose-related responses is important. Thus, Winter and Petti (1987), while recording that 8-OH-DPAT (0.3-3.0 mg/kg) reduced performance in the rat radial maze, noted, in an observation of at least equal importance, that a lower dose of 0.1 mg/kg enhanced performance by 173%. The inhibitory and facilitatory effects may reflect a presynaptic action in the raphe nuclei followed by a postsynaptic receptor activation in the forebrain, respectively. In any case, 5-HT, receptor agonist potential must be carefully examined to eliminate or reveal opposing roles. 

Bartolomeo A. C., Morris H., and Boast C. A. (1997). Arecoline via miniosmotic pump improves AF64A-impaired radial maze performance in rats A possible model of Alzheimer s disease. Neurobiol. Leam. Mem. 68 333-342. 

Barbiturates have been shown to affect spontaneous alternation and radial maze performance in mice (ref. 150). Rats treated prenatally with aluminum showed a deficit in radial maze acquisition (ref. 151). Neonatal clonidine treatment delayed choice of a water rewarded arm in a T-maze by water deprived rats which had been pretrained in this maze vith food reward (ref. 33). 

Hebb-Villiams maze problem solving behavior, behavior in a radial maze or a... 

Santucci D, Rankin J, Laviola G, et al. 1995. Eight-arm radial maze performance and hippocampal nerve growth factor levels in adult C57B1/6J mice following prenatal exposure to aluminum. [Abstract]. Behavioral brain research in naturalistic and semi-naturalistic settings (NATO ASI series D, No. 82). 

Wolf MC, Leander JD (2003) SR141716A, a cannabinoid CB1 receptor antagonist, improves memory in a delayed radial maze task. Eur J Pharmacol 477(3) 213-17... 

After behavioral evaluation in the 8-arm radial maze task, the rat s brain was fixed and apoptosis was identified in the hippocampal CA1 by TUNEL assay. Apoptotic cells were found in vehicle-treated rats on the 7th day after ischemia (mean F S.E.M. 78.4 F 5.7 TUNEL-positive cells/mm2). As shown in Fig. 8,... 

Wolff MC, Overshiner C, Leander JD. 5-HT6 receptor antagonists enhance memory in radial maze and object recognition tasks. Soc Neurosci Abstr 2002 28 586.1. 

Ennaceur A. Effects of lesions of the substantia innominata ventra pallidum globus pallidus and medial septum on rat s performance in object-recognition and radial-maze tasks physostigmine and amphetamine treatments. Pharmacol Res 1998 38 251-263. 

Another task in which short-term memory can be differentiated from long-term memory is the radial maze (Olton 1986). This apparatus consists of a central platform with arms radiating from it like the spokes of a wheel. A hungry rat or a mouse is placed in the centre of the maze and can find food at the end of each arm. An ideal performance during a trial would be for the animal to visit each arm once to collect food. This task requires therefore that, during a trial, the animal... 

The radial maze we use consists of a central platform (30 cm in diameter) with 8 arms (68 x 10 cm) surrounded by walls (Height = 10 cm). A food receptacle is located at the end of each arm. The receptacle is in the form of a small hole in the floor rendering the food invisible from the entrance to the arm. The apparatus is constructed of black Plexiglas and is elevated 80 cm above the floor. 

Fig. 10. The effects of scopolamine on the 3 parameters measured (errors, running times, response strategy) during the radial maze task in the rat (mean of 3 sessions). Note the dose-dependent increase in the number of errors and running times, with a statistically significant decrease in response strategy occurring at the highest dose.

Another aspect of radial maze performance is the use of positive motivation (food reward), in contrast to the aversive motivations maintaining the passive avoidance and Morris maze procedures. Data suggesting drug-induced cognitive impairment are more convincing if the impairments span the different motivational systems maintaining the behaviors. 

The principal variant to the radial maze procedure described above is the inclusion of a reference memory component, by baiting only some of the arms (Beatty Bierley 1985). In addition to remembering which arms were visited during a particular session... 

Another approach to reference memory is to use the radial maze task as a repeated acquisition task with different arms being baited during each test session (Levin et al. 1998). In this way the task can be modified to evaluate exclusively reference memory. As with repeated passive avoidance sessions, this use of the radial maze is very time-consuming, and we do not recommend it for safety pharmacology purposes. 

Beatty WW, Bierley RA (1985) Scopolamine degrades working memory but spares spatial reference memory dissimilarity of cholinergic effect and restriction of distal visual cues. Pharmacol Biochem Behav 23 1-6 Cassel JC, Kelche C (1989) Scopolamine treatment and fimbria-fomix lesions mimetic effects on radial maze performance. Physiol Behav 46 347-353 Levin ED, Bettegowda C, Weaver T, Christopher NC (1998) Nicotine-dizocilpine interactions and working and reference memory performance in rats in the radial-arm maze. Pharmacol Biochem Behav 61 335-340 Magni S, Krekule I, Bures J (1979) Radial maze type as a determinant of the choice behavior of rats. J Neurosci Meth 1 343-352... 

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