scholarly journals Neurogenesis-mediated forgetting of complex paired-associates memories

2021 ◽  
Author(s):  
Jonathan R Epp ◽  
Leigh CP Botly ◽  
Sheena Josselyn ◽  
Paul W Frankland
Keyword(s):  
Adult Neurogenesis ◽  
Voluntary Exercise ◽  
Mammalian Brain ◽  
Reversal Task ◽  
Paired Associates ◽  
Location Task ◽  
The Stability ◽  
Adult Mammalian Brain ◽  
Critical Structure

The hippocampus is a critical structure involved in many forms of learning and memory. It is also one of the only regions in the adult mammalian brain that continues to generate new neurons throughout adulthood. This process of adult neurogenesis may increase the plasticity of the hippocampus which could be beneficial for learning but has also been demonstrated to decrease the stability of previously acquired memories. Here we test whether increased production of new neurons following the formation of a gradually acquired paired-associates task will result in forgetting of this type of memory. We trained mice in a touchscreen-based object/location task and then increased neurogenesis using voluntary exercise. Our results indicate that mice with increased neurogenesis show poor recall of the previously established memory. When subsequently exposed to a reversal task we also show that mice with increased neurogenesis require fewer correction trials to acquire the new task contingencies. This suggests that prior forgetting reduces perseveration on the now outdated memory. Together our results add to a growing body of literature which indicates the important role of adult neurogenesis in destabilizing previously acquired memories to allow for flexible encoding of new memories.

scholarly journals The Microtubule Severing Protein Katanin Regulates Proliferation of Neuronal Progenitors in Embryonic and Adult Neurogenesis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Franco L. Lombino ◽  
Mary Muhia ◽  
Jeffrey Lopez-Rojas ◽  
Monika S. Brill ◽  
Edda Thies ◽  
...  
Keyword(s):  
Adult Neurogenesis ◽  
Critical Role ◽  
Mammalian Brain ◽  
Cellular Functions ◽  
Microtubule Severing ◽  
Neuronal Progenitor ◽  
Neuronal Progenitors ◽  
Adult Hippocampus

Abstract Microtubule severing regulates cytoskeletal rearrangement underlying various cellular functions. Katanin, a heterodimer, consisting of catalytic (p60) and regulatory (p80) subunits severs dynamic microtubules to modulate several stages of cell division. The role of p60 katanin in the mammalian brain with respect to embryonic and adult neurogenesis is poorly understood. Here, we generated a Katna1 knockout mouse and found that consistent with a critical role of katanin in mitosis, constitutive homozygous Katna1 depletion is lethal. Katanin p60 haploinsufficiency induced an accumulation of neuronal progenitors in the subventricular zone during corticogenesis, and impaired their proliferation in the adult hippocampus dentate gyrus (DG) subgranular zone. This did not compromise DG plasticity or spatial and contextual learning and memory tasks employed in our study, consistent with the interpretation that adult neurogenesis may be associated with selective forms of hippocampal-dependent cognitive processes. Our data identify a critical role for the microtubule-severing protein katanin p60 in regulating neuronal progenitor proliferation in vivo during embryonic development and adult neurogenesis.

scholarly journals Overexpression of cdk4 and cyclinD1 triggers greater expansion of neural stem cells in the adult mouse brain

2011 ◽  
Vol 208 (5) ◽  
pp. 937-948 ◽  
Author(s):  
Benedetta Artegiani ◽  
Dirk Lindemann ◽  
Federico Calegari
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Adult Neurogenesis ◽  
Adult Mouse ◽  
Physiological Role ◽  
Mammalian Brain ◽  
Temporal Control ◽  
Somatic Stem Cells

Neural stem cells (NSCs) in the adult mammalian brain generate neurons and glia throughout life. However, the physiological role of adult neurogenesis and the use of NSCs for therapy are highly controversial. One factor hampering the study and manipulation of neurogenesis is that NSCs, like most adult somatic stem cells, are difficult to expand and their switch to differentiation is hard to control. In this study, we show that acute overexpression of the cdk4 (cyclin-dependent kinase 4)–cyclinD1 complex in the adult mouse hippocampus cell-autonomously increases the expansion of neural stem and progenitor cells while inhibiting neurogenesis. Importantly, we developed a system that allows the temporal control of cdk4–cyclinD1 overexpression, which can be used to increase the number of neurons generated from the pool of manipulated precursor cells. Beside providing a proof of principle that expansion versus differentiation of somatic stem cells can be controlled in vivo, our study describes, to the best of our knowledge, the first acute and inducible temporal control of neurogenesis in the mammalian brain, which may be critical for identifying the role of adult neurogenesis, using NSCs for therapy, and, perhaps, extending our findings to other adult somatic stem cells.

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.

Role of affect in short-term memory for paired associates.

1968 ◽  
Vol 78 (3, Pt.1) ◽  
pp. 494-501 ◽  
Author(s):  
Calvin F. Nodine ◽  
James H. Korn
Keyword(s):  
Short Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Paired Associates

Role of melatonin in regulating neurogenesis: Implications for the neurodegenerative pathology and analogous therapeutics for Alzheimer’s disease

2020 ◽  
Vol 3 (2) ◽  
pp. 216-242 ◽  
Author(s):  
Mayuri Shukla ◽  
Areechun Sotthibundhu ◽  
Piyarat Govitrapong
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Adult Neurogenesis ◽  
Adult Brain ◽  
Therapeutic Approaches ◽  
Therapeutic Implications ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Progenitor Cell Proliferation

The revelation of adult brain exhibiting neurogenesis has established that the brain possesses great plasticity and that neurons could be spawned in the neurogenic zones where hippocampal adult neurogenesis attributes to learning and memory processes. With strong implications in brain functional homeostasis, aging and cognition, various aspects of adult neurogenesis reveal exuberant mechanistic associations thereby further aiding in facilitating the therapeutic approaches regarding the development of neurodegenerative processes in Alzheimer’s Disease (AD). Impaired neurogenesis has been significantly evident in AD with compromised hippocampal function and cognitive deficits. Melatonin the pineal indolamine augments neurogenesis and has been linked to AD development as its levels are compromised with disease progression. Here, in this review, we discuss and appraise the mechanisms via which melatonin regulates neurogenesis in pathophysiological conditions which would unravel the molecular basis in such conditions and its role in endogenous brain repair. Also, its components as key regulators of neural stem and progenitor cell proliferation and differentiation in the embryonic and adult brain would aid in accentuating the therapeutic implications of this indoleamine in line of prevention and treatment of AD.   

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

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