The evidence and concept of adult neurogenesis have been documented in the scientific literature since the 1960s, with research conducted by Altman (1962) and Altman and Das (1965). These studies have demonstrated that adult neurogenesis occurs in the brains of rodents, mainly in the dentate gyrus. The dentate gyrus in humans forms part of the hippocampal formation, located in the medial temporal lobe of the brain. It has a vital role in learning, memory formation, and spatial navigation (Amaral et al., 2007; Rolls, 2013).

Neurogenesis is the process by which new neurons are generated from neural stem or progenitor cells (Gage, 2002; Zhao et al., 2008). Progenitor cells are early descendants of stem cells that can differentiate into specific cell types but have more limited potential than stem cells. In the context of neurogenesis, neural progenitor cells can divide and produce different types of neurons or glial cells, but they cannot self-renew indefinitely, unlike true stem cells (Gage, 2000; Temple, 2001).

Once thought to be limited to early developmental stages, it is now widely recognised that neurogenesis continues throughout adulthood in specific regions of the brain, especially the subgranular zone of the dentate gyrus in the hippocampus and the subventricular zone next to the lateral ventricles (Eriksson et al., 1998; Ming & Song, 2011).

Adult neurogenesis plays a vital role in learning, memory, mood regulation, and cognitive flexibility (Kempermann, 2011; Gonçalves et al., 2016; Aimone et al., 2014; Sahay et al., 2011). These findings revolutionized our understanding of brain plasticity and challenged the long-standing belief that the adult brain is a static, nonrenewable organ (Altman, 1962; Altman & Das, 1965; Eriksson et al., 1998).

These investigations also demonstrated that neurogenesis in the brains of older, mature adults was less evident compared to younger rodents (Kuhn, Dickinson-Anson, & Gage, 1996; Ben Abdallah et al., 2010), despite physiological evidence indicating that neurogenesis declines rapidly as rodents mature (Amrein et al., 2007). However, the positive aspect of this decline in neurogenesis was that it did not cease entirely (Spalding et al., 2013; Boldrini et al., 2018; Moreno-Jiménez et al., 2019).

This discovery suggested that adult neurogenesis could offer ongoing neurological benefits, potentially leading to positive cognitive, physical, and behavioural outcomes that might endure lifelong. What this implied for Altman and Das (1965) was that the brain was not fixed, a notion that, at the time, remained the prevailing dogma (Altman, 1962; Altman & Das, 1965; Ormerod & Galea, 2012). Therefore, continual engagement in learning activities and physical exercise is essential as a lifelong commitment.

The lifelong accumulation of knowledge, refined insights, and practical understanding, along with the skills, knowledge, experiences and wisdom gained by mature members of society, significantly enhances mentorship, social insights, and cultural continuity; all of which benefit society (Carstensen, 2006; Lindenberger, 2014). Mature adults act as reservoirs of experience. Here, we observe individuals who have gained life wisdom, practical judgement, and deep contextual understanding, enriching society in ways that only develop over time; all of which continually bring benefits to society (Baltes & Staudinger, 2000).

Furthermore, their lifelong empirical tenacity to achieve, their wisdom, and their ability to keep learning, adapting, and growing mentally, emotionally, and socially (as evidenced over the years and supported by neurogenesis) support the idea that age does not hinder holistic growth or creativity. In fact, their real-world achievements and accumulated insights and knowledge highlight an often-overlooked truth: experience cannot be bought with money or replaced by youth. This kind of social insight, knowledge, experience, and wisdom is gained only through time, effort, and ongoing engagement in life’s challenges, and it is something we should all recognise and celebrate (Carstensen, 2006; Lindenberger, 2014; Baltes & Staudinger, 2000).

Although the........

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