This study examined whether theta oscillations were compromised by the type of circadian disruption that impairs hippocampal-dependent memory processes. In prior studies on Siberian hamsters, we developed a one-time light treatment that eliminated circadian timing in the central pacemaker, the suprachiasmatic nucleus (SCN). These arrhythmic animals had impaired hippocampal-dependent memory whereas animals made arrhythmic with SCN lesions did not. The current study examined whether theta oscillations are compromised by the same light treatment that produced memory impairments in these animals. We found that both methods of inducing circadian-arrhythmia shortened theta episodes in the EEG by nearly 50%. SCN-lesioned animals, however, exhibited a 3-fold increase in the number of theta episodes and more than doubled the total time that theta dominated the EEG compared to SCN-intact circadian-arrhythmic animals. Video tracking showed that changes in theta were paralleled by similar changes in exploration behavior. These results suggest that the circadian-arrhythmic SCN interferes with hippocampal memory encoding by fragmenting theta oscillations. SCN-lesioned animals can, however, compensate for the shortened theta episodes by increasing their frequency. Implications for rhythm coherence and theta sequence models of memory formation are discussed.

Objectives Undergraduate ultrasound education is becoming increasingly important, but its expansion is limited by time, space and the availability of trained faculty. In order to validate an alternative and more accessible teaching model, our aim was to assess whether combining teleguidance and peer‐assisted learning to teach ultrasound is as effective as traditional in‐person methods. Methods Peer instructors taught 47 second‐year medical students ocular ultrasound via either teleguidance or traditional in‐person methods. Proficiency was assessed using a multiple‐choice knowledge test and objective structured clinical examination (OSCE). Confidence, overall experience, and experience with a peer instructor were measured using a 5‐point Likert scale. Two one‐sided t‐tests were used to measure equivalency between the two groups. The null hypothesis that the two groups were not different was rejected when P < 0.05. Results The teleguidance group performed as well as the traditional in‐person group in terms of knowledge change, confidence change, OSCE time and OSCE score (p = 0.011, p = 0.006, p = 0.005 and  = 0.004, respectively, indicating the two groups are statistically equivalent). The teleguidance group rated the experience highly overall (4.06/5), but less than the traditional group (4.47/5; P = 0.448, indicating statistical difference). Peer instruction was rated 4.35/5 overall. Conclusion Peer‐instructed teleguidance was equivalent to in‐person instruction with respect to knowledge change, confidence gain and OSCE performance in basic ocular ultrasound.

ObjectiveAlcohol use disorder (AUD) is a leading cause of preventable death and is a frequent diagnosis in the emergency department (ED). Treatment in the ED, however, typically focuses on managing the sequelae of AUD, such as acute withdrawal, rather than addressing the underlying addiction. For many patients, these ED encounters are a missed opportunity to connect with medication for AUD. In 2020, our ED created a pathway to offer patients with AUD treatment with naltrexone (NTX) during their ED visit. The aim of this study was to identify what barriers and facilitators patients perceive to NTX initiation in the ED.MethodsAdopting the theoretical framework of the behavior change wheel (BCW), we conducted qualitative interviews with patients to elicit their perspectives on ED initiation of NTX. Interviews were coded and analyzed using both inductive and deductive approaches. Themes were categorized according to patients’ capabilities, opportunities, and motivations. Barriers were then mapped through the BCW to design interventions that will improve our treatment pathway.ResultsTwenty‐eight patients with AUD were interviewed. Facilitators of accepting NTX included having recently experienced sequelae of AUD, rapid management of withdrawal symptoms by the ED provider, having a choice between intramuscular and oral formulations of the medication, and experiencing positive interactions in the ED that destigmatized the patient's AUD. Barriers to accepting treatment included lack of provider knowledge about NTX, dependence on alcohol as self‐treatment for psychiatric trauma and physical pain, perceived discriminatory treatment and stigma about AUD, aversion to potential side effects, and lack of access to continued treatment.ConclusionsInitiation of treatment of AUD with NTX in the ED is acceptable to patients and can be facilitated by knowledgeable ED providers who create a destigmatizing environment, effectively manage withdrawal symptoms, and connect patients to providers who will continue treatment.

We tested the hypothesis that a temporary period of circadian arrhythmia would transiently impair recall of an aversive memory in Siberian hamsters (Phodopus sungorus). Unlike mice or rats, circadian arrhythmia is easily induced in this species by a one-time manipulation of their ambient lighting [i.e., the disruptive phase shift (DPS) protocol]. Hamsters were conditioned to associate footshocks with a shock chamber (context) and with a predictive auditory tone (cue), and then exposed to the DPS protocol. Following DPS, animals either became arrhythmic (ARR), reentrained to the light-dark cycle (ENT), or became arrhythmic for &lt; 14 days before their circadian locomotor rhythms spontaneously recovered and reentrained (ARR-ENT). Tests for contextual memory showed that freezing was decreased 9–10 days post-DPS when both ARR and ARR-ENT groups were arrhythmic. Once ARR-ENT animals reentrained (day 41), however, freezing was elevated back to Pre-DPS levels and did not differ from those observed in ENT hamsters. ENT animals maintained high levels of freezing at both time points, whereas, freezing remained low in ARR hamsters. In contrast to contextual responses, cued responses were unaffected by circadian arrhythmia; all three groups exhibited elevated levels of freezing in response to the tones. The differential impact of circadian arrhythmia on contextual versus cued associative memory suggests that arrhythmia preferentially impacts memory processes that depend on the hippocampus.