The Effects of Telencephalic Lesions on Visually Mediated Prey Orienting Behavior in the Leopard Frog <i>(Rana pipiens)</i>

Abstract

In this paper, we report studies aimed at characterizing the relationship between forebrain and midbrain systems involved in the control of prey orienting behavior in the leopard frog. In frogs, unilateral forebrain lesions, like unilateral tectal lobe lesions, have their most prominent effects in the contralateral monocular visual field. Such lesions produce partial reductions in response frequency in the binocular visual field as well. Similar sequelae follow unilateral tectal lobe removal. These findings suggest that the effects of unilateral forebrain removal can be largely attributed to removal of a facilitating influence on the tectal lobe on the same side of the brain. In the case of both forebrain and midbrain lesions, behavior was assayed not only in terms of the frequency with which animals responded to stimuli at various locations in the visual field (as is usually done) but also in terms of the latency of whatever responses were observed. A striking inverse relationship between response frequency and response latency was found, both in lesioned and in normal frogs. This relationship has not previously been noticed, doesn’t appear to be an obvious consequence of any existing models of the neuronal circuitry underlying anuran orienting behavior, and is difficult to account for in terms of the time scales associated with axonal conduction times and synaptic delays. It may be easier to account for in terms of the responses to perturbation of large interacting systems of neurons, and this possibility seems worthy of further exploration.

Animal Foraging and the Evolution of Goal‐Directed Cognition

“…However, in vertebrates behaviors modified by dopamine begin to involve a broader class of motion, not necessarily related to moving toward food. For example, frogs and toads both maintain dopaminergic control of visuomotor focus on prey times (Buxbaum-Conradi & Ewert, 1999;Patton & Grobstein, 1998). Similar dopaminergic involvement in visuomotor focus is seen in rats and humans (Barrett, Bell, Watson, & King, 2004;Dursun, Wright, & Reveley, 1999;Evenden, Turpin, Oliver, & Jennings, 1993).…”

“…In the evolutionary history of vertebrates, it is therefore possible to witness a development from the dopaminergic striatal control of visuomotor focus in frogs and toads (Buxbaum-Conradi & Ewert, 1999;Patton & Grobstein, 1998) to the similarly controlled maintenance of ideas in working memory (Schultz et al, 1995). What lies in the transition from early chordates to vertebrates is not so well understood.…”

Selective attention without a neocortex

“…Electrical stimulation of sites in the tectum evokes prey-catching behavior directed to locations in the front and contralateral side of the visual field, consistent with the eye-centered map in the tectum (Ewert, 1970). Conversely, after removal of the tectal lobe on one side (Figure 4B–C), frogs are completely unresponsive to prey items (e.g., mealworms) that are placed in the contralateral monocular visual field (Kostyk & Grobstein, 1982; 1987), and have longer reaction times for stimuli in the binocular visual field (Patton & Grobstein, 1998a). When the tectum is disconnected from downstream motor circuits by unilateral hemisection, frogs can detect prey items at all locations in the visual field but they no longer orient accurately for stimuli located on one side (Kostyk & Grobstein, 1982; 1987).…”

Peptides in frog brain areas processing visual information

“…Descending striatal fibers terminate in the ad and av (Lázá r and Kozicz, 1990;Marín et al, 1997) and behavioral studies indicate their involvement in the control of visually evoked responses (Finkenstä dt, 1989;Patton and Grobstein, 1998). Therefore, the peptide-ir elements of the striatum will also be described.…”