Responses of Single Neurons in the Toad’s Caudal Ventral Striatum to Moving Visual Stimuli and Test of Their Efferent Projection by Extracellular Antidromic Stimulation/Recording Techniques

Abstract

Previous work in anuran amphibians has shown that activity in the caudal ventral striatum correlates with visuomotor activity: orienting responses toward prey fail to occur after striatal lesions. Thus it has been suggested that the striatum influences visually guided behavior. Therefore, the present study investigates visual response properties from neurons recorded in the striatum. Extracellular recordings of 104 single neurons of the cane toad’s (Bufo marinus) caudal ventral striatum (STR) reveal five different response properties: resting discharge activity uninfluenced by the visual test stimuli (group STR1, 24.0%); resting discharge activity increased by any moving visual object (STR2, 31.7%); preference to moving compact objects (STR3, 15.4%); preference to certain configurational moving objects (STR4a and b, 13.5%), and resting activity reduced by visual stimuli (STR5, 15.4%). The receptive fields of these neurons encompassed the contralateral (46%) or the entire field of vision (54%). Of the neurons recorded in the striatum, 34% responded to electrical stimuli applied in the rostral diencephalon to the ipsilateral lateral forebrain bundle (LFB) which connects the striatum with the optic tectum (e.g. either directly or via pretectum or tegmentum). Various electrically driven STR neurons (40%) have axons that project caudally through the LFB, which was suggested by their antidromic activation in response to electrical stimuli applied to the LFB in the rostral diencephalon. In the present study, the main striatal output is mediated by ‘motion detectors’ (STR2) and ‘compact object perceivers’ (STR3). It is suggested that the caudal ventral striatum is involved in visual attentional processes that allow the translation of perception into action.

Nitric Oxide Synthase and NADPH Diaphorase Distribution in the Bullfrog <i>(Rana catesbeiana)</i> CNS: Pathways and Functional Implications

“…It is likely that NO participates in higher level visual processing in these areas, as it does in other vertebrates [Cudeiro and Sillito, 2006]. For example, presence of NO-releasing cells in the ventral striatum of bullfrogs suggests a role in visuomotor coordination [Buxbaum-Conradi and Ewert, 1999]. Functionally, NO participates in the remodeling of retinotectal projections during ontogeny in X. laevis [Rentería and Constantine-Paton, 1996;Cogen and Cohen-Cory, 2000] and might act broadly to regulate synaptic plasticity at adulthood.…”

Apomorphine Alters Prey-Catching Patterns in the Common Toad: Behavioral Experiments and ¹⁴C-2-Deoxyglucose Brain Mapping Studies

“…Structures involved are the retina, the tectum, and the pretectum as components of a stimulus-response mediated releasing system and the striatum and the pretectum as components of its modulating loop [Ewert et al, 1999].…”

“…Activity in (certain) striatal efferent neurons attenuates pretectal activity and along with this the pretecto-tectal inhibitory influences, thus gating the tectal releasing system for prey-oriented turning [Ewert, 1984[Ewert, , 1992[Ewert, , 1997Ewert et al, , 1999. Several types of efferent striatal visual cells were described by Buxbaum-Conradi and Ewert [1999]. For striato-pretectal connections see Wilczynski and Northcutt [1983b], Lázár and Kozicz [1990], Marín et al [1997c], and Matsumoto et al [1991].…”

“…11; see vOB y LS y vMP Y A Y R) [Hoffmann, 1973;Kicliter and Northcutt, 1975;Northcutt and Royce, 1975;Northcutt and Kicliter, 1980;Neary and Wilczynski, 1980]. Previous 14 C-2DG studies have shown that activity in the ventral medial pallium is associated with conditioning [see Finkenstädt, 1989;Finkenstädt et al, 1985;Merkel-Harff and Ewert, 1991;Papini et al, 1995;Ewert et al, 1994bEwert et al, , 1999. The increase in glucose utilization in the ventral medial pallium might also result from the action of APO as a positive reinforcer [e.g.…”

“…As part of a research program to determine the role of dopamine in visuomotor function in amphibians [Ewert et al, 1999], we showed that the dopamine D 2 /D 1 -receptor agonist apomorphine (APO) modulates the components of prey-catching behavior in a dose dependent manner [for a characterization of D 1 and D 2 dopamine receptors in Rana pipiens see Chu et al, 1994]. In common toads (Bufo bufo), systemic administration of APO led, on one hand, to an attenuation in the activity of prey-oriented turning and locomotion, and, on the other hand, to a facilitation of prey snapping [Glagow and Ewert, 1997a].…”