Understanding the neural mechanisms underlying behavior presents a formidable challenge requiring a well-chosen model system and sophisticated experimental tools. Vocalizations of the African clawed frog (Xenopus laevis) are an exceptionally well suited model system for this objective. In this species, a simplified mechanism of vocal production allows straightforward interpretations of neuronal activity with respect to behavior, and neural mechanisms of calling can be studied in vitro because fictive vocalizations can be elicited in the isolated brain. Furthermore, the vocalizations of Xenopus are sexually differentiated, and rapid androgen-induced masculinization of female vocalizations provides an invaluable opportunity for determining how new behavior arises from existing neural circuits in response to steroid hormones. In my talk, I will discuss how the vocal central pattern generators (CPG) are constructed, and an unexpected discovery of feedback pathways within the CPG that play a critical role in the rhythm generation. In addition, I will describe our work developing a technique to deliver transgenes into the frog nervous system.
会場：東京大学駒場１キャンパス KOMCEE West B1F レクチャーホール・MMホール（キャンパスマップ）
Fish as model systems for vocal communication and hearing research
Teleost fish comprise the largest group of extant vertebrates displaying the greatest diversity in sound producing apparatus and sensory hearing structures for social communication and orientation. Neural circuitry controlling vocal behaviour in vertebrates seems to have evolved from conserved brain areas found in ancestral fish before they diverged into the major clades. Thus, studies that investigate acoustic communication systems in this taxon are important to gain a comprehensive understanding of the fundamental mechanisms underlying social acoustic communication.
Moreover, studying organisms from an early diverging vertebrate lineage such as fish is essential to comprehend the evolution and function of the vertebrate inner ear, since many early developmental events are evolutionary conserved.
In this talk I will focus on the social role and physiological mechanisms controlling acoustic communication in toadfishes (Batrachoididae). I will further discuss current research on auditory plasticity and development of auditory function using both models – toadfish and zebrafish (Danio rerio, Cyprinidae).
In recent linguistic theory and the Minimalist Program in particular, the interface between linguistic and non-linguistic cognition has come to be of critical importance in the study of the nature of the faculty of language. In this regard, Un-Cartesian linguistics has radicalized old ideas about the nature of this interface, according to which the intrusion of language into the brain has reformatted primate cognition, creating a novel neural infrastructure in which human-specific thought can arise and without which it is unavailable. If so, there is no interface between two independent systems of language and thought in humans, and generativity in language and human-specific thought are the same. New evidence for this hypothesis comes from thought disturbances (psychopathologies). Un-Cartesian linguistics predicts that such disturbances must involve language disturbances. I will review recent evidence from my lab testing this prediction in three clinical populations: children and adolescents with autism who do not develop language in any modality, whether in production or in comprehension; patients with formal thought disorder, a symptom of schizophrenia; and patients with Huntington’s disease, an early dementia. It turns out that in all three cases, there is strong evidence that thought disintegration is mirrored in language disintegration, in a way that appears to be independent of non-linguistic neuro-psychological deficits. It is thus potentially key to better understanding these disorders and the connection between language and thought at large.