Dear Colleagues,

Research on the structure and function of the nervous system has revealed crucial information in our understanding of how this structure helps animals to perceive the environment and respond with adaptive behaviors. A wide range of studies, from the apparent simple nervous system of the hydra to the neural complexity of non-human primates, show scientist today that there is still a long way to go to comprehend such sophistication. A similarity and divergence comparative analysis in the animal kingdom is a must, considering that this effort can accelerate our knowledge on the structure, function, and evolution of the nervous system, and can consequently provide us with more tools to face the still unresolved field of neural diseases and disorders. Thus, a Special Issue on the comparative neuroanatomy and neurobiology in animals is imperative because remarkable information is produced constantly, and this Special Issue will provide an appropriate venue to share such findings.

As editors, we invite you to submit your original research or a review to this Special Issue. No doubt your contribution will enable us to better understand how the nervous system contributes to the life and evolution of animals, and to understand the underlying basis of misfunctions. 

Dr. Jorge Manzo
Prof. Dr. Porfirio Carrillo-Castilla
Dr. Genaro A. Coria-Avila
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Animals is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• evolution
• brain
• neuron
• glia
• disorders
• diseases
• cognition
• biophysics
• neurophysiology
• neurochemistry

Title: Androgen receptors and sociosexual behaviors in mammals: The limits of generalization
Authors: Anders Ågmo
Affiliation: The Arctic University of Norway
Abstract: Some androgens, for example testosterone, may be aromatized to estradiol both in males and females. The enzyme responsible for aromatization, aromatase, is not only widely distributed in the body of both sexes but is also found in all mammalian species that have been subjected to study. This means that under physiological conditions, the actions of the main androgen, testosterone, can be mediated either by the androgen receptor or any of the estrogen receptors. Indeed, many of the effects of testosterone and some other androgens are known to be mediated by estrogen rather than androgen receptors. This fact is often overlooked, leading to considerable confusion as to which receptor is responsible for what. The purpose of the present review is to summarize the effects of androgens, mainly of testicular, adrenal, and ovarian origin, acting on the androgen receptor. To do so, it must be shown that simultaneous activation of estrogen receptors does not contribute to the observed effects of androgens. It turns out that there are important species differences within the mammalian class, making it risky to generalize observations made in one species to another species. This is of utmost relevance for the habit of treating mice as small rats, or rats as big mice, or humans as two-footed rats.

Title: Sucrose Binge Drinking during adolescence and later in adulthood modify pro and matureBDNF levels in the nucleus accumbens of male rats
Authors: 1Simsek Z, 1Torres A, 1Wilson N and 1Vazquez-Sanroman D
Affiliation: 1Department of Anatomy and Cell Biology Oklahoma State Center for Health Sciences
Abstract: As a natural stimulus, sugar activated similar neural circuits involved in mediating reward. During adolescence, prime sucrose exposure may lead to a sensitization of the reward system, changing the response to rewarding stimuli in the adult stage. There are specific brain areas involved in reward and food preference behavior, one of the most important is the mesocorticolimbic dopamine system, with dopaminergic projections traveling from the midbrain ventral tegmental area to the nucleus accumbens. Brain-Derived Neurotrophic Factor (BDNF) is a potential regulator of neural plasticity and is involved in dopamine-reward modulation in the brain, then a potential candidate for understanding the neural basis of sucrose-induced reward. This study aimed to determine the effect of sucrose exposure during adolescence and adulthood using a sucrose binge drinking model and analyze the levels of proBDNF and MatureBDNF in the PFC and NAc, brain areas relevant to the cortical-mesolimbic system. Adolescent rats were exposed to 5 daily sucrose binge drinking sessions (SBD) followed by two months of sucrose-free and subsequent re-exposure to SBD. A separate group was sucrose-naïve during adolescence and exposed to one single SBD session as adults; levels of proBDNF and MatureBDNF were determined by an ELISA immunoassay kit. We found out that adolescent rats showed significantly higher levels of sucrose binge drinking at 5% concentration over 15% concentration. Main changes in pro and matureBDNF levels were observed in the NAc of animals exposed to SBD during adolescence and later as adults; more importantly, those changes are sucrose-dependent. SBD during adolescence changes the subsequent sucrose response as an adult, which may be mediated by the NAc pro-and mature BDNF.

Title: Functional anatomy of cranial nerves
Authors: Hugo Libreros-Jiménez, Jorge Manzo, María Toledo-Cárdenas, Deissy Herrera-Covarrubias, Gonzalo Aranda-Abreu, Luis García-Hernández, Genaro Coria-Avila, Fausto Rojas-Duran, María Hernández-Aguilar*
Affiliation: Universidad Veracruzana, Xalapa, Mexico
Abstract: The cranial nerves consist of 12 pairs that supply the head, neck, thorax, and abdomen. Each nerve's origin is determined by its specific functions. The olfactory nerve, corresponding to cranial nerve I, supply the upper nasal cavity. Nerves II and IV originate at the midbrain level, while the cranial nerve III originates from the oculomotor and Edinger-Westphal nuclei located also in the midbrain. Nerves V, VI, VII, and VIII originate from the brain stem pons. Cranial nerve IX shares a similar origin with cranial nerve X, originating from multiple nuclei within the brainstem, making it a multimodal nerve. The XI cranial nerve, known as the accessory or spinal nerve, originates from nuclei in the medulla oblongata and the spinal cord. Finally, the XII cranial nerve, or hypoglossal nerve, originates from the motor nucleus in the medulla oblongata. The cranial nerves serve various functions, including transmitting olfactory, visual, auditory, and taste information. They also control the movement of the eye muscles and regulate the opening and closing of the pupil. Additionally, they play a role in facial sensation, chewing, facial expressions, tongue movement, balance, laryngeal muscles, pharynx, swallowing, and cephalic and pheromone detection. These twelve nerves are present in all mammals and serve similar functions to those in humans. This review aims to provide updated information on the structure, innervation, neurotransmitters, and consequences that arise when these nerves are affected.