MSM in HIV-Prevention Trials are Sexual Partners With Each Other: An Ancillary Study to the EXPLORE Intervention

The EXPLORE study evaluated a behavioral intervention to prevent HIV seroconversion among men who have sex with men (MSM). The present ancillary study enrolled 345 EXPLORE participants at one study site (Boston) and assessed high-risk sexual behavior with other EXPLORE participants. It also assessed sexual intentions across other EXPLORE participants, HIV-negative individuals, and unknown HIV serostatus partners. Thirty-one percent reported having sex with another EXPLORE participant: 27% unprotected receptive oral sex with ejaculation (UO), 30% unprotected insertive anal sex (UIA), and 34% reported unprotected receptive anal sex (URA). Significant relationships between intentions to engage in UO, UIA, and URA, and type of partner emerged with intentions to engage in UO, UIA, and URA higher in HIV-negative partners, other EXPLORE participants, and unknown-HIV serostatus partners. Future HIV-prevention studies recruiting MSM at increased sexual risk of HIV infection should address participants potentially becoming sexual partners with each other.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44009/1/10461_2005_Article_9025.pd

The Hippocamposeptal Pathway Generates Rhythmic Firing of GABAergic Neurons in the Medial Septum and Diagonal Bands: An Investigation Using a Complete Septohippocampal Preparation In Vitro

International audienceThe medial septum diagonal band area (MS/DB) projects to the hippocampus through the fornix/fimbria pathway and is implicated in generating hippocampal theta oscillations. The hippocampus also projects back to the MS/DB, but very little is known functionally about this input. Here, we investigated the physiological role of hippocamposeptal feedback to the MS/DB in a complete in vitro septohippocampal preparation containing the intact interconnecting fornix/fimbria pathway. We demonstrated that carbachol-induced rhythmic theta-like hippocampal oscillations recorded extracellularly were synchronized with powerful rhythmic IPSPs in whole-cell recorded MS/DB neurons. Interestingly, we found that these IPSPs evoked rebound spiking in GABAergic MS/DB neurons. In contrast, putative cholinergic and glutamatergic MS/DB neurons responded only weakly with rebound spiking and, as a result, were mostly silent during theta-like oscillations. We next determined the mechanism underlying the rebound spiking that followed the IPSPs in MS/DB GABAergic neurons using phasic electrical stimulation of the fornix/fimbria pathway. We demonstrate that the increased rebound spiking was attributable to the activation of I(h) current, because it was significantly reduced by low concentrations of the I(h) antagonist ZD7288 [4-(N-ethyl-N-phenylamino)-1,2-dimethyl-6-(methylamino) pyridinium chloride]. Together, these results suggest that rhythmical activity in hippocampus is transferred to the MS/DB and can preferentially phase the spiking of GABAergic MS/DB neurons because of their significant expression of I(h) currents. Our data demonstrate that hippocamposeptal inhibition facilitates theta rhythmic discharges in MS/DB GABAergic neurons while favoring the inhibition of most ACh and glutamate neurons

In vitro activation of the medial septum—Diagonal band complex generates atropine-sensitive and atropine-resistant hippocampal theta rhythm: An investigation using a complete septohippocampal preparation

International audienceThe medial septum and diagonal band complex (MS-DB) is believed to play a key role in generating theta oscillations in the hippocampus, a phenomenon critical for learning and memory. Although the importance of the MS-DB in hippocampal theta rhythm generation is generally accepted, it remains to be determined whether the MS-DB alone can generate hippocampal oscillations or is only a transducer of rhythmic activity from other brain areas. Secondly, it is known that hippocampal theta rhythm can be separated into an atropine-sensitive and insensitive component. However, it remains to be established if the MS-DB can generate both types of rhythm. To answer these questions, we used a new in vitro rat septohippocampal preparation placed in a hermetically separated two side recording chamber. We showed that carbachol activation of the MS-DB generated large theta oscillations in the CA1 and CA3 regions of the hippocampus. These oscillations were blocked by applying either the GABA(A) receptor antagonist bicuculline or the AMPA/kainate antagonist DNQX to the hippocampus. Interestingly, the application of the muscarinic receptor antagonist atropine produced only a partial decrease in the amplitude, without modification of the frequency, of theta. These results show for the first time, that upon optimal excitation, the MS-DB alone is able to generate hippocampal oscillations in the theta frequency band. Moreover, these MS-DB generated theta oscillations are mediated by muscarinic and nonmuscarinic receptors and have a pharmacological profile similar to theta rhythm observed in awake animals

Health care reform and integrated care: A golden opportunity for preventive psychiatry

The Affordable Care Act (ACA) includes provisions to shift the U.S. health care system to address achieving wellness rather than just treating illness. In this Open Forum, the Prevention Committee of the Group for the Advancement of Psychiatry describes opportunities created by the ACA for improving prevention of mental illnesses and promotion of mental health. These include improved coverage of preventive services, models to integrate primary and behavioral health care, and establishment of the National Prevention, Health Promotion, and Public Health Council, which has developed a National Prevention Strategy. The authors describe the important role that psychiatrists can play in advancing prevention of mental illnesses, in particular by working to incorporate prevention strategies in integrated care initiatives and by collaborating with primary care providers to screen for risk factors and promote mental and emotional well-being