Subventricular zone-derived, newly generated neurons populate several olfactory and limbic forebrain regions

Abstract

Neurogenesis persists in several regions of the adult mammalian brain. Although the hippocampus and olfactory bulb are most commonly studied in the context of adult neurogenesis, there is an increasing body of evidence in support of neurogenesis occurring outside of these two regions. The current study expands upon previous data by showing newborn neurons with a mature phenotype are located in several olfactory and limbic structures outside of the hippocampus and olfactory bulb, where we previously described DCX/BrdU immature neurons. Notably, newborn neurons with a mature neuronal phenotype are found in the olfactory tubercles, anterior olfactory nuclei, tenia tecta, islands of Calleja, amygdala and lateral entorhinal cortex. The appearance of newborn neurons with a mature phenotype in these regions suggests that these structures are destinations, and that newborn neurons are not simply passing through these structures. In light of the increasing body of evidence for neurogenesis in these, and other olfactory, limbic and striatal structures, we hypothesize that brain regions displaying adult neurogenesis are functionally linked.

Distribution and fate of DCX/PSA-NCAM expressing cells in the adult mammalian cortex: A local reservoir for adult cortical neuroplasticity?

“…Recent studies suggest the presence of adult-born neurons or immature neurons in several regions of the adult mammalian central nervous system outside the canonical neurogenic niches, including cortical areas (Kaplan, 1981;Dayer et al, 2005;Takemura, 2005;Shapiro et al, 2007aShapiro et al, , 2007bShapiro et al, 2009;de la Rosa-Prieto et al, 2010), subcortical areas (Bédard et al, 2002;Bernier et al, 2002;De Marchis et al, 2004;Vessal et al, 2007;Okuda et al, 2009;Pierce and Xu, 2010;Ehninger et al, 2011;Dirian et al, 2014;Ernst et al, 2014;Luzzati et al, 2014), and the spinal cord (Shechter et al, 2007). In humans, histological and carbon-14 dating approaches revealed that adult-born interneurons could integrate into the striatum (Ernst et al, 2014).…”

“…Innovative and meticulous studies have led to the identification of at least three different cell types that give rise to new neurons outside the canonical neurogenic niches of the (healthy) adult mammalian brain. The first was BrdU-positive neuroblasts emigrating from the subventricular zone, which are reported to give rise to a small number of new-born neurons in some ventral brain regions in the early to young postnatal period in mice and rats (De Marchis et al, 2004;Shapiro et al, 2007a;Shapiro et al, 2007b;Shapiro et al, 2009), as well as in young rabbits and monkeys, where the migratory routes of these immature neurons are well documented (Bédard et al, 2002;Bernier et al, 2002;Luzzati et al, 2003). However, since this form of neurogenesis was only observed in the very early postnatal period in these mammals, critics stated that this low-level neurogenic process was merely a protraction of an incomplete developmental neurogenesis (reviewed in Bonfanti and Peretto, 2011).…”

“…Whether or not some pyramidal neurons in the adult murine piriform cortex are derived from nonproliferating NG2-expressing cells (Guo et al, 2010;Richardson et al, 2011), does not exclude the contribution of subventricular zone-derived neuroblasts to the generation of neuron-specific nuclear protein (NeuN)-expressing cells in very young rodents (Shapiro et al, 2009;Shapiro et al, 2007a), nor does it exclude that prenatally produced DCX/ PSA-NCAM-expressing cells may also be present in cortical layer II of adult mammals Luzzati et al, 2009;Zhang et al, 2009;Varea et al, 2011;Rossi et al, 2014;Rubio et al, 2015). Given previous disagreements, it is possible that these three cell populations, with an assumed neuronal fate, are present in the healthy adult piriform cortex in different quantities according to age and species (e.g.…”

Enriquecimento ambiental como estratégia para promover a neurogênese na doença de Alzheimer: possível participação da fosfolipase A2

“…Neurônios que se originam na SVZ migram para o bulbo olfatório [5][6][7] . Novos neurônios residindo na SVZ também entram no neocórtex de associação (córtices pré-frontal, temporal inferior e parietal posterior) 8 , estriado 6 , córtex piriforme 9 , amídala e córtex entorrinal lateral 10 . Tem sido relatado que a neurogênese ocorre em outras áreas do cérebro adulto, tais como neocórtex 11,12 , sub-regiões CA do hipocampo (CA1, CA2-3) 13 , amídala, córtex piriforme 12 , substância negra 14 e III ventrículo 15 , mas esses dados têm sido fonte de debates e controvérsias e ainda precisam ser confirmados.…”

Proliferation, Migration, and Survival of Cells in the Telencephalon of the Ball Python, Python Regius

“…It is also important in processing information about pheromones and other olfactory or vomeronasal input, causing it to directly influence the endocrine system (Halpern and Martínez-Marcos, 2003) and behavior during confrontations with conspecifics (agonistic behavior) (Meredith and Westberry, 2004). Support for mammalian amygdalar neurogenesis has been limited to studies indicating proliferation, cell genesis, and specification in Orictolagus cuniculus (New Zealand white rabbits) (Luzzati et al, 2006), Mus musculus (laboratory mice) (Shapiro et al, 2009), and Saimiri sciureus (common squirrel monkeys) and Macaca fascicularis (crab-eating macaques) (Bernier et al, 2002). In the present study I have found the reptilian DLA/LA is a region of high proliferation, but low migration and survival, which coincides with its role, not in storage, but in encoding sensory memory.…”