Activation of the hypothalamic feeding centre upon visual prey detection

Abstract

The visual system plays a major role in food/prey recognition in diurnal animals, and food intake is regulated by the hypothalamus. However, whether and how visual information about prey is conveyed to the hypothalamic feeding centre is largely unknown. Here we perform real-time imaging of neuronal activity in freely behaving or constrained zebrafish larvae and demonstrate that prey or prey-like visual stimuli activate the hypothalamic feeding centre. Furthermore, we identify prey detector neurons in the pretectal area that project to the hypothalamic feeding centre. Ablation of the pretectum completely abolishes prey capture behaviour and neurotoxin expression in the hypothalamic area also reduces feeding. Taken together, these results suggest that the pretecto-hypothalamic pathway plays a crucial role in conveying visual information to the feeding centre. Thus, this pathway possibly converts visual food detection into feeding motivation in zebrafish.

Transposons As Tools for Functional Genomics in Vertebrate Models

“…Since the body of a zebrafish larva is transparent through all developmental stages, such transgenic fish have been used to visualize the vascular system [108], the central and peripheral nervous systems [109, 110], the regenerating processes of the sensory system and fin [111, 112], the cellular process of muscle wound repair [113], and proteolytic cleavage of the extracellular domain of a membrane protein (Neuregulin) in the motor neurons [114], among others. Also, the transgenic fish were applied to image the activity of specific neuronal populations or endothelial cells by targeted expression of a calcium indicator GCaMP [115, 116]. In addition, gene trap vectors similar to those shown in Fig.…”

“…( G ) Central nervous system and motor neurons in the spinal cord in SAIGFF213A at 1 dpf [114]. ( H ) Calcium imaging of the pretectal neurons while a larva recognizes a paramecia (prey) [115]. …”

Learning steers the ontogeny of an efficient hunting sequence in zebrafish larvae

“…Larval hunting appears as a distinct behavioural mode that is composed of several component actions chained together into a sequence [9,33,51]. While significant progress has been made in characterising the kinematics of larval zebrafish hunting in detail [6,9,43,51], and in describing the circuits and cell types involved in this behaviour [3,5,23,38,39,46,49,50], it is not known whether experience affects the ontogeny and effectiveness of their hunting sequences. To address this, we used high speed imaging and behavioural tracking of freely-swimming zebrafish larvae to compare hunting behaviour and performance between larvae that have been reared with live prey and those that have not.…”

Capturing volumetric dynamics at high speed in the brain by confocal light field microscopy

“…The high volumetric imaging speed and epi-illumination configuration together make LFM a well-suited technique to image freely moving animals, which are of great interests in neuroscience because of the extended behavioral paradigms to understand various complex brain functions 19,[36][37][38][39] . In particular, neural activity in groups of neurons during larval zebrafish's prey capture behavior, which is under extensive investigations [40][41][42][43] , has been recorded at relatively low spatial or temporal resolutions 31,44,45 .…”