A comparison of protocols for passive and discriminative avoidance learning tasks in the domestic chick

Abstract

A one-trial learning task where chicks learn that a bead of a particular shape and/or colour has a bitter taste (100% Methyl anthranilate -MeA) and subsequently avoids it on test has been widely used by research groups across the world. However, there are some differences in the results reported by different research laboratories. One important difference is found when chicks are trained on a diluted bitter taste (10 or 20% MeA) such that memory is not consolidated and fades, e.g. memory lasts for 30 min at Monash and La Trobe Universities versus 4-6 hours at the Open University (OU). Differences in protocol that may explain this apparent discrepancy are whether the chicks have seen the bead before (novelty), and whether the colour or the shape of the bead is a more important feature. In this review, we discuss these and other factors that may contribute to the differences in the characteristics of memory processing between Monash and the OU, e.g. strain, hatchery or laboratory incubated chicks, age at training. It is clear that there is a difference between passive avoidance and discriminative avoidance protocols and this may explain the differences in duration of the memory and the different stages. Is the OU task a more salient experience because of the novelty of the bead and therefore a 'stronger' learning experience? The different protocols may allow different questions to be addressed. AbstractA one-trial learning task where chicks learn that a bead of a particular shape and/or

Ultrasound exposure of the foetal chick brain: effects on learning and memory

“…In the chick, insults such as hypoxia or stress hormones during the second half of incubation are well known to be associated with loss or impairment of memory function (Camm et al, 2001; Rodricks et al, 2004, 2008). Memory processing is modulated in a number of brain areas, including the intermediate medial mesopallium (IMM), as well as the hippocampus and medial striatum (Gibbs, 2008; Gibbs and Summers, 2002; Gibbs et al, 2008a,b). In our study, the ultrasound beam (in pulsed Doppler‐mode) was positioned immediately adjacent to the midline of the IMM (Fig.…”

“…The chicks were weighed and placed in brooders according to treatment groups at 29 °C and provided with food and water ad libitum . Memory testing was performed on post‐hatch day 2 using the bead discrimination task (Gibbs and Summers, 2002; Gibbs et al, 2008a,b). Within 2 h of testing, chicks were decapitated and the brains removed and weighed.…”

Astrocytes and Interneurons in Memory Processing in the Chick Hippocampus: Roles for G-Coupled Protein Receptors, GABA(B) and mGluR1

“…The experimental procedures are described in detail elsewhere [5,15]. Briefly chicks are placed in pairs on arrival at the laboratory, each chick differentiated by their natural colour variation (a dark and a light chick for each pair).…”

The Chick as a Model for the Study of the Cellular Mechanisms and Potential Therapies for Alzheimer's Disease

“…Each chick is usually trained and tested only once. Because the pecking response requires a positive, accurate act by the bird, it also controls for effects on attentional, visual, and motor processes [47, 48]. …”