Adult-born granule cells mature through two functionally distinct states.

János Brunner,Tibor Andrási,Felix B Kleine Borgmann,Máté Neubrandt,János Szabadics,Sebastian Jessberger,Susan Van-Weert

doi:10.7554/elife.03104

Abstract

Adult-born granule cells (ABGCs) are involved in certain forms of hippocampus-dependent learning and memory. It has been proposed that young but functionally integrated ABGCs (4-weeks-old) specifically contribute to pattern separation functions of the dentate gyrus due to their heightened excitability, whereas old ABGCs (>8 weeks old) lose these capabilities. Measuring multiple cellular and integrative characteristics of 3- 10-week-old individual ABGCs, we show that ABGCs consist of two functionally distinguishable populations showing highly distinct input integration properties (one group being highly sensitive to narrow input intensity ranges while the other group linearly reports input strength) that are largely independent of the cellular age and maturation stage, suggesting that 'classmate' cells (born during the same period) can contribute to the network with fundamentally different functions. Thus, ABGCs provide two temporally overlapping but functionally distinct neuronal cell populations, adding a novel level of complexity to our understanding of how life-long neurogenesis contributes to adult brain function.

Highlights

Adult neurogenesis contributes to certain forms of hippocampus-dependent behavior and is associated with a number of neuro-psychiatric diseases (Parent and Murphy, 2008; Deng et al, 2010; Kheirbek et al, 2012; Spalding et al, 2013)
Measuring multiple cellular and integrative characteristics of 3- 10-week-old individual Adult-born granule cells (ABGCs), we show that ABGCs consist of two functionally distinguishable populations showing highly distinct input integration properties that are largely independent of the cellular age and maturation stage, suggesting that ‘classmate’ cells can contribute to the network with fundamentally different functions
The majority of the tested parameters of individual ABGCs changed continuously with age and, the distribution of the data points from individual cells was wide, without the emergence of distinguishable populations (Figure 3A–B, statistical values are indicated in the figures—see Supplementary file 1), Neuroscience reflecting the continuous maturation of these properties in accordance with previous observations (Mongiat et al, 2009; Marín-Burgin et al, 2012)

Summary

Introduction

Adult neurogenesis contributes to certain forms of hippocampus-dependent behavior and is associated with a number of neuro-psychiatric diseases (Parent and Murphy, 2008; Deng et al, 2010; Kheirbek et al, 2012; Spalding et al, 2013). Current theories on adult neurogenesis are based on the provisional correlations between the two distinct physiological functions and age-dependent maturation of cellular (including synaptic, biophysical and molecular) properties (Aimone et al, 2006, 2010; Sahay et al, 2011b). This is supported by numerous observations showing that after their birth, ABGCs undergo a continuous maturation process, lasting for 8–10 weeks. How do individual ABGCs transform from ‘young’ to ‘old’ properties? There are three testable

Methods

Results

Conclusion