Antidepressant Effect of Optogenetic Stimulation of the Medial Prefrontal Cortex

Antidepressant Effect of Optogenetic Stimulation of the Medial Prefrontal Cortex

To better define the mechanisms by which viruses depress immune function, the effect of influenza infection on the ability of macrophages to accumulate at sites of inflammation was determined. Here, we examined cellular indicators of functional activity, including the immediate early genes (IEGs) zif268 (egr1), c-fos, and arc, in the prefrontal cortex of clinically depressed humans obtained postmortem. Here we studied if ghrelin-reactive Ig are associated with anxiety and depression and with the stress-induced cortisol response in a general population of adolescents. Case report. Prefrontal cortical tissue derived from clinically depressed humans displayed significant reductions in IEG expression, consistent with a deficit in neuronal activity within this brain region. If you suspect you are suffering from depression professional help must be obtained. Interestingly, some of these changes were not observed in defeated mice that escape the deleterious consequences of the stress, i.e., resilient animals.

John’s Wort is commonly used as a mild to moderate antidepressant. The earliest and most dramatic effect of monocular deprivation (MD) is the severe loss of visual cortical responsiveness to the deprived eye (deprivation amblyopia). As far as relationships go, the thing you need to understand about young men (or men in general) – and this is coming from a man- is that a lot of them are mostly interested in one thing, among other things in a relationship and the thought of their girlfriend having Herpes kind of puts a damper on that. Brain imaging studies of depressed patients have suggested both increases and decreases in cortical activity, with a notable decrease occurring in response to negative-valence stimuli, abnormalities that are restored after successful antidepressant treatment (Mayberg, 2003; Fales et al., 2008). If you are extremely worried about it, there are medications such as Acyclovir (Valtrex) that you can take to keep the virus suppressed. These results support the hypothesis that aspects of human depression are mediated through prefrontal cortical mechanisms. Exposure of rodents to stress can modify the activity, transcriptional state, and morphological profile of neurons within the medial prefrontal cortex (mPFC) (Nikulina et al., 2004; Liston et al., 2006; Czéh et al., 2007; Radley et al., 2008; Dias-Ferreira et al., 2009).

John’s Wort and depression. These findings are consistent with the observation that mPFC lesions induce hyper-sensitive stress responses and deficits in fear extinction (Holson, 1986; Silva et al., 1986; Diorio et al., 1993; Milad and Quirk, 2002). If you or someone close to you are experiencing depression, talk with your doctor about treatment. Healthcare providers should be aware of this association and its potential implications in order to deliver better care for patients with depression or sexually transmitted infections. Careful studies have shown 70% of patients with CFS had active HHV-6 infection through the use of primary cell cultures and confirmation using assays of monoclonal antibodies specific for HHV-6 proteins and by PCR. Rodent ventral mPFC, like primate anterior cingulate cortex, is critically involved in the regulation of emotional behavior (Vogt et al., 1992; Barbas, 1995; Heidbreder and Groenewegen, 2003). Currently all data used in this study are completely de-identified and are publicly available on the NCHS web site.

Then, to directly determine the role of prefrontal cortical activity in depressive-like behaviors, we stimulated the mPFC of susceptible mice using viral-mediated expression of channel rhodopsin 2 (ChR2), a blue-light-sensitive cation channel (Adamantidis et al., 2007; Zhang et al., 2007; Airan et al., 2009; Lobo et al., 2010). A pattern of laser stimulation was delivered to mimic cortical burst firing reported in vitro (Yang et al., 1996). We hypothesized that mPFC stimulation would generate antidepressant-like behavioral responses in susceptible mice subjected to chronic social defeat stress. Nine- to 10-week-old C57BL/6J male mice (Jackson Laboratories) were used for all mouse experiments. This international gathering includes pediatric researchers, leaders in academic pediatrics, experts in child health, and practitioners. Behavioral assessments and tissue collection were conducted 1 h after the start of the animals’ dark phase. Mouse procedures were conducted in accordance with the Institutional Animal Care and Use Committee guidelines of Mount Sinai School of Medicine.

Social interaction was performed as described previously (Berton et al., 2006; Tsankova et al., 2006). In brief, mice were placed within a novel arena with a small animal cage located at one end. Each socially stressed or control mouse’s movement was monitored for 100 s during laser stimulation that was delivered in the absence of a CD1 mouse (open field behavior), followed by 100 s in the presence of a CD1 (social interaction behavior). Locomotor activity measurements (distance traveled) and information pertaining to the duration spent in the confines of the interaction zone was obtained using Ethovision 3.0 software. Genital herpes is usually sexually transmitted. All animals were acclimatized for 3 consecutive days to two-bottle choice conditions starting the day after surgery for prefrontal cortex viral infusion, before 1 additional day of choice testing (noon—noon), when experimental laser stimulation was conducted. No restriction on duration of use although at least 4 weeks of treatment is required to assess the anti-depressant effect.

However, HSV-G2CT infection completely blocked the NMDA-stimulated loss of surface AMPARs (Fig. The first laser stimulation was delivered to mice 1 h after the onset of the dark phase and the second 6 h later. Sucrose preferences were calculated as the percentage of sucrose/water consumed. Social memory was assessed during laser stimulation using a modified version of a social recognition test (Dluzen and Kreutzberg, 1993). C57BL/6J mice were surgically prepared by viral infection of ChR2-mCherry- or mCherry-expressing vectors and fixation of guide cannula over the prefrontal cortex. Three days later, experimental mice were allowed to become familiar with another C57BL/6J mouse that was 1 week younger than the experimental mouse, by placing them into this younger mouse’s home cage for 30 min on five separate occasions, each separated by 1 h. Pregnant women should not use it.

The elevated plus maze was designed using black Plexiglas fitted with white bottom surfaces to provide contrast, and tests were conducted as previously described (Monteggia et al., 2007). C57BL/6J mice received intra-mPFC ChR2-mCherry- or mCherry-expressing vectors and guide cannula. Mice were subsequently placed in the center of the plus maze and allowed to freely explore the maze for 5 min under red-lighting conditions, while laser deliveries of blue light were directed into the mPFC in a “burst-like” manner. The position of each mouse over time in the open and closed arms was monitored with videotracking equipment (Ethovision) and a ceiling-mounted camera. Herpes simplex virus (HSV) vectors driven by the IE4/5 promoter expressing ChR2 fused to mCherry [HSV-ChR2-mCherry, in HSVPrpUC, using the ChR2-mCherry DNA construct (Airan et al., 2009), or mCherry alone (in p1005/mCherry)], were prepared as described previously (Neve et al., 2005; Lobo et al., 2010). Since HSV expression is maximal on days 3–4 postinfection, all ChR2 blue light stimulation was performed on day 4. To control in vivo patterns of neuronal firing, a 200 μm (external size) optic fiber (Thor Labs) was custom modified for attachment to the cannula.
Antidepressant Effect of Optogenetic Stimulation of the Medial Prefrontal Cortex

When securing the optic fiber before in vivo laser presentations, the fiber was stripped down to the 100 μm core, so that when lowered through the guide cannula it became flush with the length of the guide, fixed at the dorsal edge of the prefrontal cortex (prelimbic region). This secure connection to the cannula is a slightly modified version from that used in previous studies (Gradinaru et al., 2007; Airan et al., 2009). Optical fibers were lowered and secured to each cannula head-mount assembly only during stimulation trials. Optical stimulations were performed similar to previously published protocols (Gradinaru et al., 2007; Airan et al., 2009). Optical fibers (Thor Labs) were connected via a FC/PC adaptor to a 473 nm blue laser diode (Crystal Lasers, BCL-473-050-M), and a stimulator (Agilent, #33220A) was used to generate blue light pulses. During all stimulations, 40 ms 100 Hz (9.9 ms spike width) blue light pulses (i.e., bursts) were delivered every 3 s to the mPFC over the duration of each behavioral test, to mimic a burst-like pattern of cortical activity (Yang et al., 1996). The intensity of the optic fiber light was verified before each use, using a light sensor (Thor Labs, S130A), and light intensity ranged from 1 to 2 mW.

Bilateral punches (15 gauge) of the ventral area of the mPFC were obtained from C57BL/6J mice as previously described (Renthal et al., 2007) after 10 continuous days of chronic social defeat stress (Berton et al., 2006), or after stimulation by a blue laser, using the same stimulation conditions used for behavioral experiments. Collected tissue was immediately frozen, and stored at −80°C until processing. Frozen human or mouse tissue was thawed in TriZol (Invitrogen) and processed according to the Invitrogen protocol. RNA was purified using RNeasy Micro columns (Qiagen) and processed as indicated via the Qiagen kit manual. Spectroscopy measurements were used to confirm that RNA had A 260/280 and A 260/230 ratios >1.8. Those on medication, including the contraceptive pill, should consult their physician for advice. This unexpected difference in infectivity suggests that the effects of G2CT expression are primarily because of disruptions in AMPAR endocytosis in excitatory neurons.

PCRs for zif268, arc, and c-fos were performed in triplicate, and quantified using the ΔΔCt method as previously described (Maze et al., 2010). One hour after optical stimulation mice infected with ChR2-mCherry or mCherry alone were anesthetized and perfused intracardially with 4% paraformaldehyde/PBS. Brains were removed and postfixed by immersion overnight in 4% paraformaldehyde and cryoprotected in 30% sucrose/PBS. Coronal sections (30 μm) were cut on a freezing microtome and processed for immunohistochemistry. Sections were preincubated in a blocking buffer containing 0.3% Triton and 3% normal donkey serum. It is active against viruses in the laboratory and in some animal studies. After washing, sections were incubated with Cy2-conjugated secondary antibody (1:1600, Jackson Immunoresearch).

Subsequently, slides were coverslipped and visualized under a microscope (100×) for capturing images of mCherry (red fluorescence), c-Fos (green fluorescence), or both merged (see Fig. 4 A). For double immunolableing of c-Fos with CaMKII (Ca2+/calmodulin-dependent protein kinase II) or GABA, sections were blocked in 3% normal donkey serum and 0.3% Triton-X in 0.1 m PBS for 1 h. Sections were subsequently incubated overnight in primary antibodies in the above blocking solution using the following antibodies: rabbit anti-c-Fos (1:500, Santa Cruz Biotechnology) and mouse anti-CaMKII (1:200, Millipore Bioscience Research Reagents) or mouse anti-GABA (1:1000, Sigma). The next day, sections were rinsed in 0.1 m PBS and placed into secondary antibodies: donkey anti-rabbit-Cy3 and donkey anti-mouse-Cy2 (1:200, Jackson ImmunoResearch) in 0.1 m PBS for 1 h. Sections were again rinsed in 0.1 m PBS, mounted and coverslipped in DEPEX. While under a combination of ketamine (100 mg/kg) and xylazine (10 mg/kg) anesthesia, experimental C57BL/6J mice were surgically infused with either viral vector that expresses ChR2 plus mCherry or mCherry alone (Lobo et al., 2010); vectors were targeted to the infralimbic and prelimbic regions of prefrontal cortex.

Specifically, a Hamilton syringe was fitted with a 33 gauge needle and filled with 1.5 μl of virus. From bregma, at the surface of the skull, the needle was lowered unilaterally at a 15° angle into the prefrontal cortex [anteroposterior (AP) = 1.75, mediolateral (ML) = 0.75, dorsoventral (DV) = 2.65], whereupon 0.4 μl of virus was delivered over 4 min. After a 5 min delay, the needle was pulled up 0.25 mm and an additional 0.4 μl of virus was delivered over 4 additional minutes. After the second infusion, the needle was left in place for 5 min to allow for diffusion. Immediately after the completion of viral infusions, 20 gauge stainless steel guide cannula (2 mm projection from the pedestal; Plastics One) were positioned directly over the viral infusion site (AP = 1.75, ML = 1.75, DV = 1.7, from bregma) above the prefrontal cortex and secured to the skull via Cerebond skull cement. All mice were allowed 3 d to recover from surgery before the start of optical stimulation experiments. Comparisons between depressed (medicated and unmedicated combined) versus control postmortem tissue were initially made for the results of RNA analyses using two tailed t tests.

Subsequently, isolated comparisons of RNA results between depressed (medicated or unmedicated) versus control postmortem tissue, between socially defeated (susceptible or unsusceptible) versus control tissue, were made by one-way ANOVAs. Analyses of social interaction, locomotor behavior in an open field, and sucrose preferences in control and susceptible mice expressing either ChR2-mCherry or mCherry during stimulation were analyzed by 2 × 2 ANOVAS (stress × virus). Significant isolated comparisons were determined via Bonferroni post hoc analyses. The comparison of social interaction behavior 24 h after stimulation with the laser was made using a two-tailed t test. Bilia AR, Gallori S, Vincieri FF. It is possible that infected neurons fail to exhibit synaptic plasticity because they are injured. Tissue was collected after obtaining consent from the next of kin, along with permission to obtain medical records, and a direct telephone interview with a primary caregiver.

For each case, blood toxicology screens were conducted and those subjects with a history of drug abuse, neurological disorders, or head injury were not included (supplemental Fig. S2, available at as supplemental material). Medical records were examined by two psychiatrists who made independent diagnoses, which were followed by a consensus diagnosis according to DSM IV criteria. The collection of human brain tissue was approved by the Institutional Review Board of University of Texas Southwestern Medical Center at Dallas. The tissue cohort consisted of 10 pairs of cases of depression and controls matched for age, brain pH, postmortem interval, and RNA integrity number. Samples of the anterior division of the anterior cingulate cortex (Brodmann area 24) were removed from fresh brain specimens at the level of the rostrum of the anterior cingulate gyrus, the point at which the gyrus curves above and below the corpus callosum. Tissue samples were snap frozen and kept at −80°C until processing for qPCR analysis of zif268, c-fos and arc mRNA expression.

Depressed individuals that were being treated with antidepressants at the time of death were separated from those that were not; however, all subjects were symptomatically depressed at the time of death. Comparisons of each IEG were made between controls, depressed medicated, and depressed unmedicated cases, to reveal potential medication effects.

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