Principles of cognitive rehabilitation in TBI: An integrative neuroscience approach
Mark J. Ashley, David A. Hovda in Traumatic Brain Injury, 2017
Exciting experiments in the past two decades have demonstrated that new neurons continually form in the brain of adult animals, including primates and humans.46–50 New neurons were first found in the brains of adult songbirds in areas of the brain associated with song production. Then, new granule cells were found in the hippocampus of adult chickadees; then, in rats and primates.47 The same pattern of neuronal generation has been found in the hippocampus of adult humans.46,48 Recently in monkeys, new neurons were found to be migrating to the neocortex from stem cells in the region of the ventricles.50 Adult neurogenesis results in continual influx of neurons that are (temporarily) immature and, therefore, structurally plastic. The hope is that the immature cells can take on functions of mature, adult cells. Although this premise has not been verified yet, adult neurogenesis can have important implications for our understanding of the mechanisms of neural plasticity in general and recovery of function following brain lesions in particular.46,49,51
Neurogenesis in the Adult and Aging Brain
David R. Riddle in Brain Aging, 2007
Interest in adult neurogenesis increased tremendously in the 1980s after Nottebohm demonstrated seasonally regulated neurogenesis in the song nuclei of songbirds and provided evidence that adult neurogenesis subserved a neural function (reviewed in [6, 7]). Nottebohm’s analyses left no doubt that tritiated thymidine labeled cells in the adult bird brain were neurons, and evidence that the production of new neurons peaks at the time birds acquire new songs provided a compelling indication that adult neurogenesis is functionally significant, at least in birds. Subsequent studies demonstrated that neurogenesis also was ongoing in the hippocampus of adult birds and that the extent of hippocampal neurogenesis correlated both seasonally and across species with seed-storing, a behavior that depends on hippocampally dependent spatial learning [8–10]. Spurred in part by the dramatic findings in avian species, interest in adult neurogenesis in mammals increased precipitously into the 1990s, with several laboratories publishing seminal investigations of the nature and extent of neurogenesis in the adult mammalian brain (e.g., [11–15]). In addition to critical studies assessing adult neurogenesis in vivo using radioactive thymidine and the thymidine analog bromodeoxyuridine (BrdU), demonstrations that cells with stem cell properties could be isolated from the adult brain established a source for new neurons in the adult brain (e.g., [16–19]). Although the debate continues regarding the extent of adult neurogenesis across brain regions and across species [20–23], clearly new neurons are continually produced in some regions of the adult mammalian brain, even in humans [24], new neurons are integrated into functional circuits, and the ongoing neuronal turnover is significant for some functions.
Can Physical Activity Prevent or Treat Clinical Depression? 1
Henning Budde, Mirko Wegner in The Exercise Effect on Mental Health, 2018
Exercise treatments activate molecular and cellular cascades that support neurogenic processes (Voss, Vivar, Kramer, & van Praag 2013). Neurogenesis refers to the process of generating new neurons from precursor cells. Depression is associated with regional reductions in hippocampal volume (Videbech & Ravnkilde 2004). These morphological abnormalities in depressed patients have been attributed to deficits in adult neurogenesis, and antidepressants may work by inhibiting or reversing neurogenic impairments (Duman 2005).
Effects of fractionated whole-brain irradiation on cellular composition and cognitive function in the rat brain
Published in International Journal of Radiation Biology, 2018
Soňa Bálentová, Eva Hajtmanová, Barbora Filová, Veronika Borbélyová, Ján Lehotský, Marian Adamkov
Neurogenesis is a process of continual production of new neurons from neural stem/progenitor cells. During adulthood this occur in a number of brain structures, predominantly in two specific regions, the subgranular zone (SGZ) in the dentate gyrus (DG) of the hippocampus, and the subventricular zone (SVZ) of the lateral ventricles (LV). The progeny of the SVZ stem/progenitor cells migrate through the rostral migratory stream (RMS) to the olfactory bulb (OB) and integrate into preexisting functional circuits (Doetsch et al. 1997; Kempermann 2002; Alvarez-Buylla and Lim 2004). Adult neurogenesis is a very effective and coordinated process, influenced by a numerous physiological, pathological and pharmacological stimuli. Recent studies have revealed the functional effect on the cellular input of new neurons and their contributions to neurocognitive functions under both normal and pathological conditions (Deng et al. 2010).
Gut dysbiosis impairs hippocampal plasticity and behaviors by remodeling serum metabolome
Published in Gut Microbes, 2022
Guoqiang Liu, Quntao Yu, Bo Tan, Xiao Ke, Chen Zhang, Hao Li, Tongmei Zhang, Youming Lu
In this study, we demonstrated that gut dysbiosis in early-life impaired hippocampal neurogenesis that was restored by reconstructing a normal microbiota. Adult neurogenesis is an important process in regulating brain function and behavior. Reduction of adult neurogenesis has been associated with several psychiatric disorders, such as anxiety, depression, and memory loss.51 Neurogenesis has been reported to be orchestrated by several intrinsic and extrinsic factors, such as inflammatory cytokines, neurotransmitters, physical activity, and dietary intake.52 In addition, Ly6Chi monocytes were reported to be involved in modulating hippocampal neurogenesis in ABX-treated mice.53 Indoles, microbial metabolites of dietary tryptophan, were found to increase adult neurogenesis via the aryl hydrocarbon receptor pathway.54 Gut microbiota from chronic stress-treated mice decreased neurogenesis in healthy mice by impairing the Trp metabolism.55 In this study, the effect of gut dysbiosis on neurogenesis may be driven by multiple aspects, such as immune cell infiltration and circulating metabolites changes.
Polyunsaturated fatty acids and endocannabinoids in health and disease
Published in Nutritional Neuroscience, 2018
Hércules Rezende Freitas, Alinny Rosendo Isaac, Renato Malcher-Lopes, Bruno Lourenço Diaz, Isis Hara Trevenzoli, Ricardo Augusto De Melo Reis
Adult neurogenesis is a dynamic process that modulates synaptic plasticity in the brain and influences memory, learning and humor, occurring in response to intrinsic and environmental factors.155 Several recent reports have shown that cannabinoids play a direct modulatory role in adult neurogenesis156 and in postnatal oligodendrogenesis.157 Neurogenesis greatly influences synaptic reorganization of the olfactory bulb and hippocampal memory-dependent behavior.158 Recently, it was shown that the sustained activation of the mammalian target of rapamycin 1 (mTOR 1) is an important regulator of neurogenesis in the ventricular and subventricular zones, and the stimulation of CB1 receptors positively interferes in this pathway.159
Related Knowledge Centers
- Dentate Gyrus
- Granule Cell
- Lateral Ventricles
- Hippocampus
- Neural Stem Cell
- Neurogenesis
- Neuron
- Prenatal Development
- Subgranular Zone
- Subventricular Zone