Neuroscience
-
Paclitaxel (PTX) is one of the most commonly used chemotherapeutic agents for various cancer diseases. Despite its advantages, PTX also causes behavioral deficits related to nervous-system dysfunction, such as neuropathic pain, depression, anxiety, and cognitive impairments. The prefrontal cortex (PFC) is one of the areas that is susceptible to adverse effects of chemotherapeutic agents. ⋯ RNA sequencing and in-depth gene expression analysis of the PFC in paired vehicle and PTX-treated mice showed that PTX induced 1755 differentially expressed genes in the PFCs of male and female mice. Quantitative real-time RT-PCR verified that some gene expressions in the medial PFC (mPFC) were related to neurotransmission. In conclusion, this study identified a sex-biased effect of PTX on PFC function and gene expression, which provides a foundation for future studies to explore the precise mechanisms of PTX-induced behavioral deficits.
-
Vascular dementia (VD) is a major cognitive disorder originated from a blood flow disruption in the brain. This process leads to chronic cerebral ischemia that deeply affects neuronal tissues and lipid homeostasis. The understanding of cerebral lipid dynamics during chronic ischemia can reveal biomarkers and novel pharmacological targets for the treatment of VD. ⋯ Decanoic acid was increased after 30 days of BCCAO model. Partial least squares discriminant analysis (PLS-DA) could discriminate between BCCAO group and the control group, in which γ-linolenic acid (m/z 277) ion and stearic acid (m/z 283) had the highest discrimination potential. Taken together, these findings indicate that lipid dynamics are altered in chronic ischemia-induced by BCCAO in rats and indicate potential biomarkers and pharmacological targets for VD.
-
Compared with the biological paradigms of classical conditioning, non-adaptive computational models are not capable of realistically simulating the biological behavioural functions of the hippocampal regions, because of their implausible requirement for a large number of learning trials, which can be on the order of hundreds. Additionally, these models did not attain a unified, final stable state even after hundreds of learning trials. Conversely, the output response has a different threshold for similar tasks in various models with prolonged transient response of unspecified status via the training or even testing phases. ⋯ The results of the Green model showed a significant improvement confirmed by empirical studies of different tasks. In addition, the results indicated that the model outperforms the previously published models. All the obtained results successfully and quickly attained a stable, desired final state (with a unified concluding state of either "1" or "0") with a significantly shorter transient duration.
-
Neurons from several brain regions resonate in the theta frequency range (4-12 Hz), displaying a higher voltage response to oscillatory currents at a preferred 'resonant' frequency (fR). Subthreshold resonance could influence spiking and contribute to the selective entrainment of neurons during the network oscillatory activity that accompanies several cognitive processes. Neurons from different regions display resonance in specific theta subranges, suggesting a functional specialization. ⋯ In all the neurons studied, fR inversely correlated with the effective input resistance (Rin), a measurable variable that depends on passive and active membrane features. We showed that resonance can be adjusted by manipulations mimicking naturally occurring processes, as the incorporation of a virtual constant conductance or cell depolarization, in a way that preserves the fR-Rin relationship. The modulation of frequency selectivity influences firing by shifting spike frequency and timing, which could influence neuronal communication in an active network.
-
Vestibular organs of Amniotes contain two types of sensory cells, named Type I and Type II hair cells. While Type II hair cells are contacted by several small bouton nerve terminals, Type I hair cells receive a giant terminal, called a calyx, which encloses their basolateral membrane almost completely. Both hair cell types release glutamate, which depolarizes the afferent terminal by binding to AMPA post-synaptic receptors. ⋯ Simple diffusion of K+ between the cleft and the extracellular compartment appeared substantially restricted by the calyx inner membrane, with the ion channels and active transporters playing a crucial role in regulating intercellular [K+]. Calyx recordings were consistent with K+ leaving the synaptic cleft through postsynaptic voltage-gated K+ channels involving KV1 and KV7 subunits. The above scenario is consistent with direct depolarization and hyperpolarization of the calyx membrane potential by intercellular K+.