| Description |
One of the central goals of neuroscience is to understand how various animal behaviors are coordinated by the central nervous system. In many vertebrates, rhythmic outputs of neurons are known to be regulated by the neural networks called central pattern generators (CPGs) in the brainstem and the spinal cord. To understand the mechanism of CPG, the vocal behavior of African clawed frog, Xenopus laevis, has been used as a model system for more than a decade. Although numbers of research have been conducted to elucidate details of how populations of neurons in the vocal CPGs play crucial roles in generating Xenopus vocalization, the focus has been placed on the electrical and anatomical properties of neurons and neural circuitry, and less is known about molecular properties of neurons. To further explore the neural mechanisms underlying behavior, it is critical to identify neurochemicals that can activate or inhibit the specific neurons. With this premise, we have applied a technique called constellation pharmacology to the dorsal tegmental area of the medulla (DTAM), a region containing a component of the CPG to control male courtship calls in X. laevis. Using this method, various pharmacological agents were applied to the dissociated DTAM neurons while responses of each cells were simultaneously recorded by imaging calcium signal; based on the cell size and the response profiles to the applied pharmacological agents, every imaged cell was categorized into two major neural classes that can be further subdivided into multiple subclasses. One subset of dissociated DTAM neurons was sensitive to iv respond to both NMDA and GABA/Glycine and was considered as a putative fast trill neuron (FTN), a type of premotor neuron discovered to play a key role in generating a male courtship call. Further examination of these cells via constellation pharmacology revealed that some of these putative FTNs responded to substance P and acetylcholine. |
