Stress and psychiatric illness have been associated with a dysregulation of glutamatergic neurotransmission. Recently, positive allosteric modulators (PAMs) of the metabotropic glutamate 2 (mGlu2) receptor have been found to exert antidepressant-like activity in rats performing under a differential reinforcement of low rate (DRL) 72-s schedule. An autoreceptor role at glutamatergic synapses is ...

Lesion studies show that the hippocampus is critically involved in timing behavior, but so far there has been little analysis of how it might encode time. We recorded the activity of 266 CA1 neurons, 51 CA3 neurons, and 219 entorhinal neurons from rats performing on a differential reinforcement of low rates (DRL) 15 sec schedule in which reinforcement was contingent on responses that occurred a...

Rhamnolipid biosurfactants produced mainly by Pseudomonas sp. had been reported to possess a wide range of potential industrial application. These biosurfactants are produced as monorhamnolipid (MRL) and di-rhamnolipid (DRL) congeners. The present study deals with rhamnolipid biosurfactants produced by three bacterial isolates from crude oil. Biosurfactants produced by one of the strains (named...

Deep reinforcement learning (DRL) methods such as the Deep Q-Network (DQN) have achieved state-of-the-art results in a variety of challenging, high-dimensional domains. This success is mainly attributed to the power of deep neural networks to learn rich domain representations for approximating the value function or policy. Batch reinforcement learning methods with linear representations, on the...

Scopolamine, a non-selective muscarinic receptor antagonist has widespread central nervous system effects. Muscarinic receptors located in the central nervous system play a vital role in the modulation of impulsivity. The objective of the current study was to evaluate the effect of scopolamine on impulsivity using differential-reinforcement-of-low-rate 72-s schedule (DRL-72s) and to demonstrate...

The synaptic Ras/Rap-GTPase-activating protein (SynGAP) regulates specific intracellular events following N-methyl-d-aspartate receptor (NMDAR) activation. Here, the impact of SynGAP heterozygous knockout (SG+/-) on NMDAR-dependent functions was assessed using different positive reinforcement schedules in instrumental conditioning. The knockout did not affect the temporal control of operant res...

We study the problem of generating interpretable and verifiable policies through reinforcement learning. Unlike the popular Deep Reinforcement Learning (DRL) paradigm, in which the policy is represented by a neural network, the aim in Programmatically Interpretable Reinforcement Learning (PIRL) is to find a policy that can be represented in a high-level programming language. Such programmatic p...

A critical component to enabling intelligent reasoning in partially observable environments is memory. Despite this importance, Deep Reinforcement Learning (DRL) agents have so far used relatively simple memory architectures, with the main methods to overcome partial observability being either a temporal convolution over the past k frames or an LSTM layer. More recent work (Oh et al., 2016) has...

The effects of multiple-site, intradentate, colchicine injections on the performance of a temporal, 'differential reinforcement of low rates of responding' (DRL-20s) task and a spatial, 'delayed non-matching-to-place' (DNMTP) task in a plus-maze were investigated in rats trained in both tasks prior to the lesion. Quantitative analysis revealed a greater than 86% reduction in the dentate gyrus (...