During Running in Place, Grid Cells Integrate Elapsed Time and Distance Run.

The spatial scale of grid cells may be provided by self-generated motion information or by external sensory information from environmental cues. To determine whether grid cell activity reflects distance traveled or elapsed time independent of external information, we recorded grid cells as animals ran in place on a treadmill. Grid cell activity was only weakly influenced by location, but most grid cells and other neurons recorded from the same electrodes strongly signaled a combination of distance and time, with some signaling only distance or time.

Carcinogenic and inflammatory effects of plutonium-nitrate retention in an exposed nuclear worker and beagle dogs.

Purpose: Plutonium-nitrate has a moderately rapid translocation rate from the lung to blood stream. Previous studies have shown an unexpected retention of soluble plutonium in the beagles and human case studied here. The inflammatory responses that may be associated with long-term exposure to ionizing radiation were characterized.

Borderline personality disorder features and risk for prescription opioid use disorders.

Although there is evidence for high comorbidity between borderline personality disorder (BPD) and substance use disorders, particularly alcohol use, more research is needed on the associations between BPD and prescription opioid use because of the increasing national problem of prescription opioid misuse. The purpose of the present study was to examine relationships between BPD features and prescription opioid use, risk for misuse, consequences, and dependence features, and to determine which aspects of BPD account for these associations. As predicted, BPD features were associated with greater quantity and frequency of opioid use, risk for pain medication misuse, consequences, and dependence features.

Hippocampal "time cells": time versus path integration.

Recent studies have reported the existence of hippocampal "time cells," neurons that fire at particular moments during periods when behavior and location are relatively constant. However, an alternative explanation of apparent time coding is that hippocampal neurons "path integrate" to encode the distance an animal has traveled. Here, we examined hippocampal neuronal firing patterns as rats ran in place on a treadmill, thus "clamping" behavior and location, while we varied the treadmill speed to distinguish time elapsed from distance traveled.