Agmatine enhances neurogenesis by increasing ERK1/2 expression, and suppresses astrogenesis by decreasing BMP 2,4 and SMAD 1,5,8 expression in subventricular zone neural stem cells.

AIM: Our study aimed to demonstrate whether agmatine (Ag) could regulate proliferation and cell fate determination of subventricular zone neural stem cells (SVZ NSCs). MAIN METHODS: SVZ NSCs were grown in the presence of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) (20ng/ml) until 4days in vitro (DIV) and later the culture medium was replaced without EGF and bFGF until 11 DIV in the absence (EGF/bFGF(+/-)/Ag(-)) or presence of agmatine (EGF/bFGF(+/-)/Ag(+)). Another set SVZ NSCs were maintained with EGF and bFGF until 11 DIV without (EGF/bFGF(+/+)/Ag(-)) or with agmatine treatment (EGF/bFGF(+/+)/Ag(+)). Agmatine's effect on proliferation and cell death (H and PI staining and Caspase-3 immunostaining) was examined at DIV 4 and 11. Agmatine's (100µM) effect on cell fate determination was confirmed by immunostaining and Western blot at 11 DIV. KEY FINDINGS: Agmatine treatment reduced the neurosphere size and total cell count number dose-dependently in all the experimental groups both at DIV 4 and11. Immunoblotting and staining results showed that agmatine increased the Tuj1 and Microtubule-associated protein 2 (MAP2) and decreased the Glial fibrillary acidic protein (GFAP) with no change in the Oligo2 protein expressions. This neurogenesis effect of agmatine seems to have a relation with Extracellular-signal-regulated kinases (ERK1/2) activation and anti-astrogenesis effect is thought to be related with the suppression of Bone morphogenetic proteins (BMP) 2,4 and contraction of Sma and Mad (SMAD) 1,5,8 protein expression. SIGNIFICANCE: This model could be an invaluable tool to study whether agmatine treated SVZ NSC transplantation to the central nervous system (CNS) injury could trigger neurogenesis and decrypt the full range of molecular events involved during neurogenesis in vivo as evidenced in vitro.

Basketball training increases striatum volume.

The striatum is associated with the learning and retention of motor skills. Several studies have shown that motor learning induces neuronal changes in the striatum. We investigated whether macroscopic change in striatum volume occurs in a segment of the human population who learned basketball-related motor skills and practiced them throughout their entire athletic life. Three-dimensional magnetic resonance imaging volumetry was performed in basketball players and healthy controls, and striatum volumes were compared based on basketball proficiency, region and side. We identified morphological enlargement in the striatum of basketball players in comparison with controls. Our results suggest that continued practice and repetitive performance of basketball-related motor skills may induce plastic structural changes in the human striatum.

Experience-dependent plasticity of cerebellar vermis in basketball players.

The cerebellum is involved in the learning and retention of motor skills. Using animal and human models, a number of studies have shown that long-term motor skill training induces structural and functional plasticity in the cerebellum. The aim of this study was to investigate whether macroscopic alteration in the volume of cerebellum occurs in basketball players who had learned complex motor skills and practiced them intensively for a long time. Three-dimensional magnetic resonance imaging volumetry was performed in basketball players (n = 19) and healthy controls (n = 20), and the volumes of cerebellum and vermian lobules were compared between two groups. Although there was no macroscopic plasticity detected in the cerebellum as a whole, detailed parcellation of cerebellum revealed morphological enlargement in the vermian lobules VI-VII (declive, folium, and tuber) of basketball players (P < 0.0166), which might then be interpreted as evidence for plasticity. This finding suggests that the extensive practice and performance of sports-related motor skills activate structural plasticity of vermian lobules in human cerebellum and suggests that vermian VI-VII plays an important role in motor learning.

Evaluation of morphological plasticity in the cerebella of basketball players with MRI.

Cerebellum is a key structure involved in motor learning and coordination. In animal models, motor skill learning increased the volume of molecular layer and the number of synapses on Purkinje cells in the cerebellar cortex. The aim of this study is to investigate whether the analogous change of cerebellar volume occurs in human population who learn specialized motor skills and practice them intensively for a long time. Magnetic resonance image (MRI)-based cerebellar volumetry was performed in basketball players and matched controls with V-works image software. Total brain volume, absolute and relative cerebellar volumes were compared between two groups. There was no significant group difference in the total brain volume, the absolute and the relative cerebellar volume. Thus we could not detect structural change in the cerebellum of this athlete group in the macroscopic level.