A Hypothesis About the Role of Adult Neurogenesis in Hippocampal Function

Physiology ◽  
2004 ◽  
Vol 19 (5) ◽  
pp. 253-261 ◽  
Author(s):  
Alejandro F. Schinder ◽  
Fred H. Gage
Keyword(s):  
Adult Neurogenesis ◽  
Hippocampal Neurogenesis ◽  
Adult Hippocampal Neurogenesis ◽  
Hippocampal Function ◽  
Hippocampal Plasticity ◽  
Functional Relevance ◽  
And Function ◽  
Precise Role

The functional relevance of adult hippocampal neurogenesis has long been a matter of intense experimentation and debate, but the precise role of new neurons has not been sufficiently elaborated. Here we propose a hypothesis in which specific features of newly generated neurons contribute to hippocampal plasticity and function and discuss the most recent and relevant findings in the context of the proposed hypothesis.

scholarly journals Functional Role of Adult Hippocampal Neurogenesis as a Therapeutic Strategy for Mental Disorders

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Heechul Jun ◽  
Syed Mohammed Qasim Hussaini ◽  
Michael J. Rigby ◽  
Mi-Hyeon Jang
Keyword(s):  
Mental Disorders ◽  
Psychiatric Disorders ◽  
Adult Neurogenesis ◽  
Hippocampal Neurogenesis ◽  
Adult Hippocampal Neurogenesis ◽  
Mammalian Brain ◽  
Antidepressant Effect ◽  
Highly Correlated ◽  
Deep Brain

Adult neurogenesis, the process of generating new neurons from neural stem cells, plays significant roles in synaptic plasticity, memory, and mood regulation. In the mammalian brain, it continues to occur well into adulthood in discrete regions, namely, the hippocampus and olfactory bulb. During the past decade, significant progress has been made in understanding the mechanisms regulating adult hippocampal neurogenesis and its role in the etiology of mental disorders. In addition, adult hippocampal neurogenesis is highly correlated with the remission of the antidepressant effect. In this paper, we discuss three major psychiatric disorders, depression, schizophrenia, and drug addiction, in light of preclinical evidence used in establishing the neurobiological significance of adult neurogenesis. We interpret the significance of these results and pose questions that remain unanswered. Potential treatments which include electroconvulsive therapy, deep brain stimulation, chemical antidepressants, and exercise therapy are discussed. While consensus lacks on specific mechanisms, we highlight evidence which indicates that these treatments may function via an increase in neural progenitor proliferation and changes to the hippocampal circuitry. Establishing a significant role of adult neurogenesis in the pathogenicity of psychiatric disorders may hold the key to potential strategies toward effective treatment.

scholarly journals The Entorhinal Cortex and Adult Neurogenesis in Major Depression

2021 ◽  
Vol 22 (21) ◽  
pp. 11725
Author(s):  
Il Bin Kim ◽  
Seon-Cheol Park
Keyword(s):  
Entorhinal Cortex ◽  
Adult Neurogenesis ◽  
Potential Role ◽  
Neural Circuitry ◽  
Hippocampal Neurogenesis ◽  
Dependent Manner ◽  
Hippocampal Function ◽  
Comprehensive Understanding ◽  
Activity Dependent

Depression is characterized by impairments in adult neurogenesis. Reduced hippocampal function, which is suggestive of neurogenesis impairments, is associated with depression-related phenotypes. As adult neurogenesis operates in an activity-dependent manner, disruption of hippocampal neurogenesis in depression may be a consequence of neural circuitry impairments. In particular, the entorhinal cortex is known to have a regulatory effect on the neural circuitry related to hippocampal function and adult neurogenesis. However, a comprehensive understanding of how disruption of the neural circuitry can lead to neurogenesis impairments in depression remains unclear with respect to the regulatory role of the entorhinal cortex. This review highlights recent findings suggesting neural circuitry-regulated neurogenesis, with a focus on the potential role of the entorhinal cortex in hippocampal neurogenesis in depression-related cognitive and emotional phenotypes. Taken together, these findings may provide a better understanding of the entorhinal cortex-regulated hippocampal neurogenesis model of depression.

scholarly journals Stress-Related Dysfunction of Adult Hippocampal Neurogenesis—An Attempt for Understanding Resilience?

2021 ◽  
Vol 22 (14) ◽  
pp. 7339
Author(s):  
Julia Leschik ◽  
Beat Lutz ◽  
Antonietta Gentile
Keyword(s):  
Major Depression ◽  
Adult Neurogenesis ◽  
Current Knowledge ◽  
Functional Relation ◽  
Hippocampal Neurogenesis ◽  
Adult Hippocampal Neurogenesis ◽  
Special Focus ◽  
Extrinsic Cues ◽  
Health And Disease ◽  
Newborn Neurons

Newborn neurons in the adult hippocampus are regulated by many intrinsic and extrinsic cues. It is well accepted that elevated glucocorticoid levels lead to downregulation of adult neurogenesis, which this review discusses as one reason why psychiatric diseases, such as major depression, develop after long-term stress exposure. In reverse, adult neurogenesis has been suggested to protect against stress-induced major depression, and hence, could serve as a resilience mechanism. In this review, we will summarize current knowledge about the functional relation of adult neurogenesis and stress in health and disease. A special focus will lie on the mechanisms underlying the cascades of events from prolonged high glucocorticoid concentrations to reduced numbers of newborn neurons. In addition to neurotransmitter and neurotrophic factor dysregulation, these mechanisms include immunomodulatory pathways, as well as microbiota changes influencing the gut-brain axis. Finally, we discuss recent findings delineating the role of adult neurogenesis in stress resilience.

Potential Role of Adult Hippocampal Neurogenesis in Traumatic Brain Injury

2021 ◽  
Vol 28 ◽  
Author(s):  
Lucas Alexandre Santos Marzano ◽  
Fabyolla Lúcia Macedo de Castro ◽  
Caroline Amaral Machado ◽  
João Luís Vieira Monteiro de Barros ◽  
Thiago Macedo e Cordeiro ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Clinical Studies ◽  
Molecular Mechanisms ◽  
Hippocampal Neurogenesis ◽  
Cognitive Outcomes ◽  
Adult Hippocampal Neurogenesis ◽  
The Brain

: Traumatic brain injury (TBI) is a serious cause of disability and death among young and adult individuals, displaying complex pathophysiology including cellular and molecular mechanisms that are not fully elucidated. Many experimental and clinical studies investigated the potential relationship between TBI and the process by which neurons are formed in the brain, known as neurogenesis. Currently, there are no available treatments for TBI’s long-term consequences being the search for novel therapeutic targets, a goal of highest scientific and clinical priority. Some studies evaluated the benefits of treatments aimed at improving neurogenesis in TBI. In this scenario, herein, we reviewed current pre-clinical studies that evaluated different approaches to improving neurogenesis after TBI while achieving better cognitive outcomes, which may consist in interesting approaches for future treatments.

scholarly journals Does Impairment of Adult Neurogenesis Contribute to Pathophysiology of Alzheimer's Disease? A Still Open Question

2021 ◽  
Vol 13 ◽  
Author(s):  
Domenica Donatella Li Puma ◽  
Roberto Piacentini ◽  
Claudio Grassi
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Adult Neurogenesis ◽  
Memory Formation ◽  
Hippocampal Neurogenesis ◽  
Synaptic Function ◽  
Adult Hippocampal Neurogenesis ◽  
Amyloid Β Protein

Adult hippocampal neurogenesis is a physiological mechanism contributing to hippocampal memory formation. Several studies associated altered hippocampal neurogenesis with aging and Alzheimer's disease (AD). However, whether amyloid-β protein (Aβ)/tau accumulation impairs adult hippocampal neurogenesis and, consequently, the hippocampal circuitry, involved in memory formation, or altered neurogenesis is an epiphenomenon of AD neuropathology contributing negligibly to the AD phenotype, is, especially in humans, still debated. The detrimental effects of Aβ/tau on synaptic function and neuronal viability have been clearly addressed both in in vitro and in vivo experimental models. Until some years ago, studies carried out on in vitro models investigating the action of Aβ/tau on proliferation and differentiation of hippocampal neural stem cells led to contrasting results, mainly due to discrepancies arising from different experimental conditions (e.g., different cellular/animal models, different Aβ and/or tau isoforms, concentrations, and/or aggregation profiles). To date, studies investigating in situ adult hippocampal neurogenesis indicate severe impairment in most of transgenic AD mice; this impairment precedes by several months cognitive dysfunction. Using experimental tools, which only became available in the last few years, research in humans indicated that hippocampal neurogenesis is altered in cognitive declined individuals affected by either mild cognitive impairment or AD as well as in normal cognitive elderly with a significant inverse relationship between the number of newly formed neurons and cognitive impairment. However, despite that such information is available, the question whether impaired neurogenesis contributes to AD pathogenesis or is a mere consequence of Aβ/pTau accumulation is not definitively answered. Herein, we attempted to shed light on this complex and very intriguing topic by reviewing relevant literature on impairment of adult neurogenesis in mouse models of AD and in AD patients analyzing the temporal relationship between the occurrence of altered neurogenesis and the appearance of AD hallmarks and cognitive dysfunctions.

scholarly journals Role of Neuronal Ras Activity in Adult Hippocampal Neurogenesis and Cognition

2011 ◽  
Vol 5 ◽  
Author(s):  
Martina Manns ◽  
Oliver Leske ◽  
Sebastian Gottfried ◽  
Zoë Bichler ◽  
Pauline Lafenêtre ◽  
...  
Keyword(s):  
Hippocampal Neurogenesis ◽  
Adult Hippocampal Neurogenesis
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