Effects of intraocular mescaline and LSD on visual-evoked responses in the rat

Modulation of responses to visual stimulus onset and offset by chronic alcohol consumption and withdrawal in the rat visual cortex and lateral geniculate nucleus

In the visual system, chronic alcohol consumption and subsequent abstinence strongly modulate processing of sensory information, which could interfere with the actions in our daily lives. Although previous studies showed histological and electrophysiological changes in the retina and visual cortex during chronic alcohol consumption and abstinence, there is still a lack of information related to the effect of alcohol on: 1) different stages of visual information processing; and 2) responses of stimulus onset (ON) and offset (OFF). In order to answer these questions, we recorded visual evoked potentials (VEPs), elicited by onset and offset of a 500-ms stimulus, following long-term alcohol consumption (8 weeks) and abstinence (3 weeks) in freely moving Wistar rats. Latency and amplitude of five components in the visual cortex (N1_VC, P2_VC, N2_VC, P3_VC, N3_VC) and three components in the lateral geniculate nucleus (P1_LGN, N1_LGN, P2_LGN) were analyzed. The results showed that long-term chronic alcohol consumption and abstinence have a strong long-term and, in some cases, irreversible impact on visual information processing. Both of these conditions modulate only the last stage of stimulus onset processing at the level of the visual cortex, but not at the level of the lateral geniculate body. Response to the stimulus offset is more susceptible to the effect of alcohol consumption and/or abstinence and is modulated at both the visual cortex and lateral geniculate nucleus levels. This modulation at different stages of the information processing chain can result in inaccurate processing of visual stimuli parameters and can lead to changes in perception of stimulus duration and intensity.

Lysergic acid diethylamide causes mouse retinal damage by up-regulating p-JAK1/p-STAT1

Purpose: Lysergic acid diethylamide (LSD) is a powerful hallucinogen with high potential for abuse. There is far less known about its effects on the retina, especially the underlying mechanisms. This study was to investigate the acute toxicity of LSD on the retina of C57 mice and its mechanisms of action.Methods: C57 mice were treated with LSD at progressively increasing doses (0.2-1.2 mg/kg) intraperitoneally two times daily for 5 days, mice treated with saline served as negative control. Electroretinography (ERG) was used to test the function of the retina. Toluidine blue staining was used to detect the morphology of the retina. Enzyme-linked immunosorbent assay (ELISA) was used to measure the apoptosis-related factors. Real-time PCR and western blot techniques were used to measure expression changes of genes and proteins, respectively.Results: LSD treatment caused retinal damage, as shown by a decrease in ERG response and the loss of photoreceptor cells. LSD treatment also increased apoptosis through up-regulating the expression of p-JAK1/p-STAT1.Conclusions: Our study indicated that intraperitoneal administration of LSD-induced retinal damage of C57 mice, at least partially through regulating the JAK/STAT pathway.

The Effects of Selective Serotonin-Reuptake Inhibitor on Visual Evoked Potential in Rats

The present study was undertaken to clarify the effects of selective serotonin-reuptake inhibitors (SSRIs) on visual evoked potential (VEP) in rats. To elucidate the mechanism of action of SSRIs, some serotonin (5-HT) agonists were used. SSRIs, fluvoxamine and paroxetine, caused a reduction in the amplitudes of P1-N1, P3-N3, and N3-P4 components of VEP. The amplitude of the P1-N1 component was also reduced by the 5-HT1A agonist 8-OH-DPAT and 5-HT1B agonist anpirtoline. On the other hand, amplitudes of P3-N3 and N3-P4 components were reduced by anpirtoline and the 5-HT2 agonist DOI. These results indicate that the reduction in the amplitude of the P1-N1 component of VEP induced by SSRIs may participate in 5-HT1A and 5-HT1B receptors, and those of P3-N3 and N3-P4 components induced by SSRIs may be closely related with 5-HT1B and 5-HT2 receptors.