Neural substrates involved in the cognitive information processing in teleost fish

Abstract

Over the last few decades, it has been shown that fish, comprising the largest group of vertebrates and in many respects one of the least well studied, possess many cognitive abilities comparable to those of birds and mammals. Despite a plethora of behavioural studies assessing cognition abilities and an abundance of neuroanatomical studies, only few studies have aimed to or in fact identified the neural substrates involved in the processing of cognitive information. In this review, an overview of the currently available studies addressing the joint research topics of cognitive behaviour and neuroscience in teleosts (and elasmobranchs wherever possible) is provided, primarily focusing on two fundamentally different but complementary approaches, i.e. ablation studies and Immediate Early Gene (IEG) analyses. More recently, the latter technique has become one of the most promising methods to visualize neuronal populations activated in specific brain areas, both during a variety of cognitive as well as non-cognition-related tasks. While IEG studies may be more elegant and potentially easier to conduct, only lesion studies can help researchers find out what information animals can learn or recall prior to and following ablation of a particular brain area.

Understanding CNS Effects of Antimicrobial Drugs Using Zebrafish Models

“…It seems indeed likely, since zebrafish CNS is characterized by generally conserved neuroanatomy and neurotransmission, including well-developed glutamate-, GABA-, monoamine-, acetylcholine-, histamine-, glycine- [ 72 ], purine-ergic and endocannabinoid systems [ 73 ]. Zebrafish have a complex well-developed brain, and despite the lack of cerebral cortex and a clearly defined hippocampus, show otherwise high functionality of other structures that are neurally equivalent to those of mammals [ 74 ]. Zebrafish also exhibit a wide range of well-described behaviors, allowing the study of drug effects on locomotor, anxiety- and depression-like, and social phenotypes [ 75 , 76 , 77 ].…”

Learning Deficits and Attenuated Adaptive Stress Response After Early-Life Seizures in Zebrafish

“…Interestingly, another form of learning and memory, classical conditioning, has recently been shown to dynamically regulate excitatory synapse number in two specific areas of the zebrafish brain, the lateral and medial pallium (Dempsey et al, 2022). These telencephalic regions are proposed to be analogous to the mammalian hippocampus and amygdala, respectively (Salas et al, 2006;Ganz et al, 2014;Calvo and Schluessel, 2021;Gerlach and Wullimann, 2021), and thus the lateral pallium is likely contain neural circuits for spatial learning as well. Supporting this, goldfish with lateral pallium lesions show deficits in spatial learning (Rodríguez et al, 2002).…”

The Brilliance of the Zebrafish Model: Perception on Behavior and Alzheimer’s Disease

“…Cognition includes all the mental processing by which knowledge is acquired, retained and used in perception, learning, memory and thinking. Despite not having a defined cortex or hippocampus like the mammalian brain, zebrafishes can perform required learning and memory tasks via various parts in brain that are functionally equivalent to these structures ( Calvo and Schluessel, 2021 ; Figure 1 and Table 1 .…”

“…Among the estimated 16 neurogenic niches of the zebrafish telencephalon, the Vv of the subpallium is comparable to the sub-ventricular zone (SVZ) of the lateral ventricle of mammals and the Dl, Dp are thought to be equivalent to sub-granular zone (SGZ) between the dentate gyrus (DG) and hilum of the mammalian hippocampus ( Diotel et al, 2020 ; Ghaddar et al, 2021 ). The lateral pallium (LP) is predicted to be important for spatial learning, whereas the medial pallium (MP) is integral for avoidance learning in the zebrafish ( Calvo and Schluessel, 2021 ). The diencephalon comprises of the thalamus, pineal body, and habenula ( Vaz et al, 2019 ).…”