Oxidative stress may play a major role in the aging process and associated cognitive decline. Therefore, antioxidant treatment may alleviate age-related impairment in spatial memory. Cognitive impairment could also involve the age-related morphological alterations of the hippocampal formation. The aim of this study was to examine the relationship between the effects of deprenyl, an irreversible monoamine-oxidase B inhibitor, on spatial memory by oxidant stress and on the total number of neurons in the hippocampus CA1 region of aged male rats. In this study, 24-month-old male rats were used. Rats were divided into control and experimental groups which received an injection of deprenyl for 21 days. Learning experiments were performed for six days in the Morris water maze. Spatial learning was significantly better in deprenyl-treated rats compared to saline-treated rats. Deprenyl treatment elicited a significant decrease of lipid peroxidation in the prefrontal cortex, striatum and hippocampus regions and a significant increase of glutathione peroxidase activity in the prefrontal cortex and hippocampus. It was observed that deprenyl had no effect on superoxide dismutase activity. The total number of neurons in the hippocampus CA1 region was significantly higher in the deprenyl group than in the control group. In conclusion, we demonstrated that deprenyl increases spatial memory performance in aged male rats and this increase may be related to suppression of lipid peroxidation and alleviation of the age-related decrease of the number of neurons in the hippocampus. The results of such studies may be useful in pharmacological alleviation of the aging process.
Aging is a multifactorial process influenced by genetic factors, nutrition, and lifestyle. According to mitochondrial theory of aging, mitochondrial dysfunction is widely considered a major contributor to age-related processes. Mitochondria are both the main source and targets of detrimental reactions initiated in association with age-dependent deterioration of the cellular functions. Reactions leading to increased reactive oxygen species generation, mtDNA mutations, and oxidation of mitochondrial proteins result in subsequent induction of apoptotic events,
impaired oxidative phosphorylation capacity, mitochondrial dynamics, biogenesis and autophagy. This review summarizes the major changes of mitochondria related to aging, with emphasis on mitochondrial DNA mutations, the role of the reactive oxygen species, and structural and functional changes of mitochondria.
The study investigated second derivative of the finger arterial pressure waveform (SDFAP) in 120 healthy middle-aged subjects and in 24 subjects with essential hypertension. SDFAP consists of 5 sequential waves ‘a’-‘e’. Their normalized magnitudes (B/A, C/A, D/A, and E/A) were calculated. In multivariate regression analysis, B/A and C/A correlated only with age. D/A independently correlated with age, heart period, mean blood pressure (MBP), body height, and gender. E/A independently correlated with age and MBP. D/A and E/A were higher (0.42±0.16 vs. 0.33±0.14, p=0.05 and 0.63±0.15 vs. 0.45±0.14, p<0.001), while B/A and C/A were lower (1.04±0.16 vs. 1.20±0.17, p=0.002 and 0.09±0.15 vs. 0.26±0.20, p=0.001) in hypertensives compared to sex- and age-matched controls. After the adjustment for MBP, heart period, and body mass index (ANCOVA), independent discriminative power was preserved only for indices B/A and C/A (p = 0.001 and 0.021, respectively). Therefore, B/A and C/A provide additional information about simple clinical characteristics and might reflect the structural alteration of the arterial wall in hypertensive subjects.
The relationship between hippocampal function and aging was explored in Wistar rats using taste aversion learning by comparing the performance of adult dorsal hippocampal lesioned and fifteen-month-old intact rats with that of adult intact rats. In experiment 1 the conditioned blocking phenomenon was absent in the hippocampal and the aging rats. Unlike the adult intact rats, the hippocampal and aging rats were not impaired in acquiring a learned aversion to a cider vinegar solution (3 %) presented as a serial compound with a previously conditioned saccharin solution (0.1 %). In experiment 2 both the hippocampal and the aging rats developed reduced aversions to a saline solution (0.5 %) followed by an i.p. injection of lithium chloride (0.15 M; 2 % b.w.) if the taste solution was previously preexposed without consequences. This latent inhibition effect was similar to that seen in intact adult rats. In both experiments, the aging rats exhibited enhanced conventional learned taste aversions. It is concluded that aging is not a unitary process but induces both hippocampal dependent and hippocampal independent complex changes in the functioning of the neural circuits, implementing taste aversion learning., I. Moron, M.A. Ballesteros, A. Candido, M. Gallo., and Obsahuje bibliografii