Disambiguation of Similar Object-Place Paired Associations and the Roles of the Brain Structures in the Medial Temporal Lobe

Amnesic patients who have damage in the hippocampus and in associated areas in the medial temporal lobe suffer from remembering specific events that may or may not share similar objects and locations. Computational models, behavioral studies, and physiological findings all suggest that neural circuits in the hippocampus are suitable for representing seemingly similar events as distinctively different individual event memories. This article offers a selective review on this particular function of the hippocampus and its associates areas such as the perirhinal cortex, mostly centering upon lesion studies and physiological studies using animals. We also present recent experimental results showing that the dentate gyrus subfield of the hippocampus and perirhinal cortex are particularly important for discriminating similar paired associates between same objects and different locations, or vice versa

Forced Moves or Good Tricks in Design Space? Landmarks in the Evolution of Neural Mechanisms for Action Selection

This review considers some important landmarks in animal evolution, asking to what extent specialized action-selection mechanisms play a role in the functional architecture of different nervous system plans, and looking for “forced moves” or “good tricks” (see Dennett, D., 1995, Darwin’s Dangerous Idea, Penguin Books, London) that could possibly transfer to the design of robot control systems. A key conclusion is that while cnidarians (e.g. jellyfish) appear to have discovered some good tricks for the design of behavior-based control systems—largely lacking specialized selection mechanisms—the emergence of bilaterians may have forced the evolution of a central ganglion, or “archaic brain”, whose main function is to resolve conflicts between peripheral systems. Whilst vertebrates have many interesting selection substrates it is likely that here too the evolution of centralized structures such as the medial reticular formation and the basal ganglia may have been a forced move because of the need to limit connection costs as brains increased in size

Layered control architectures in robots and vertebrates

We revieiv recent research in robotics, neuroscience, evolutionary neurobiology, and ethology with the aim of highlighting some points of agreement and convergence. Specifically, we com pare Brooks' (1986) subsumption architecture for robot control with research in neuroscience demonstrating layered control systems in vertebrate brains, and with research in ethology that emphasizes the decomposition of control into multiple, intertwined behavior systems. From this perspective we then describe interesting parallels between the subsumption architecture and the natural layered behavior system that determines defense reactions in the rat. We then consider the action selection problem for robots and vertebrates and argue that, in addition to subsumption- like conflict resolution mechanisms, the vertebrate nervous system employs specialized selection mechanisms located in a group of central brain structures termed the basal ganglia. We suggest that similar specialized switching mechanisms might be employed in layered robot control archi tectures to provide effective and flexible action selection

Two new non-competitive mGlu1 receptor antagonists are potent tools to unravel functions of this mGlu receptor subtype

The validation of the selective, potent and systemically active non-competitive mGlu1 antagonists YM-298198 and JNJ16259685 in a physiological functional assay will facilitate elucidation of this receptor's role in brain function and as a potential drug target