The marking of construction and other valuable timber in the forests of settlement farms.

Metsänhoitajien jatkokurssit : 1956. 8

Depletion of TrkB Receptors From Adult Serotonergic Neurons Increases Brain Serotonin Levels, Enhances Energy Metabolism and Impairs Learning and Memory

Neurotrophin brain-derived neurotrophic factor (BDNF) and neurotransmitter serotonin (5-HT) regulate each other and have been implicated in several neuronal mechanisms, including neuroplasticity. We have investigated the effects of BDNF on serotonergic neurons by deleting BDNF receptor TrkB from serotonergic neurons in the adult brain. The transgenic mice show increased 5-HT and Tph2 levels with abnormal behavioral phenotype. In spite of increased food intake, the transgenic mice are significantly leaner than their wildtype littermates, which may be due to increased metabolic activity. Consistent with increased 5-HT, the proliferation of hippocampal progenitors is significantly increased, however, long-term survival of newborn cells is unchanged. Our data indicates that BDNF-TrkB signaling regulates the functional phenotype of 5-HT neurons with long-term behavioral consequences.Peer reviewe

Activation of PGC-1 protect dopaminergic neurons in the MPTP mouse model of Parkinson’s disease

Peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) is a transcriptional coactivator that is a master regulator of oxidative stress and mitochondrial metabolism. Mitochondrial dysfunction and oxidative stress occur in Parkinson’s disease (PD), but little is known about the molecular mechanisms controlling these events. We report that transgenic mice overexpressing PGC-1 in dopaminergic neurons are resistant against cell degeneration induced by the neurotoxin MPTP. The increase in neuronal viability was accompanied by elevated levels of mitochondrial antioxidants SOD2 and Trx2 in the substantia nigra of transgenic mice. To modulate PGC-1, we employed the small molecular compound resveratrol (RSV) that protected dopaminergic neurons against the MPTP-induced cell degeneration almost to the same extent as after PGC-1 overexpression. RSV also activated PGC-1 in dopaminergic SN4741 cells and enhanced PGC-1 gene transcription with increases in SOD2 and Trx2. Taken together the results reveal an important function of PGC-1 in dopaminergic neurons survival