Molecular Diversity Of Interneurons

Bitufted Cell

The morphological and neurochemical diversity of GABAergic interneuron subtypes is accompanied by an individual repertoire of receptors and ion channels, which is of major functional importance at the cellular and network level. Because of the relatively simple and structured architecture of the hippocampus, GABAergic interneurons have been mostly studied and classified in this structure, rather than in the neocortex. Hippocampal classification criteria have been often extended to analogous...

Interlaminar Connection In The Superior Colliculus

In 1972, Robinson measured the vectors of saccades evoked by electrical stimulation of the SC and provided the first detailed description of the topographical map of saccade vectors in the deeper layers of the SC (Robinson 1972). In the same year, Schiller and Stryker (1972) demonstrated that the motor map was in register with the map of visual space represented in the superficial layers. Following these demonstrations, it was supposed that the superficial and deeper layers of the SC are...

Decoding The Projection Neuron Population Output

Antennal lobe projection neurons project to the mushroom body where they send distributed collateral projections throughout the calyx. In locust, each projection neuron was estimated to make over 600 (possibly as many as 2,000) output synapses (Perez-Orive et al. 2002). More recent results (Jortner, Farivar, and Laurent, in preparation) indicate that connectivity between projection neurons and Kenyon cells is in fact a lot more widespread, but the reasoning presented below still applies. Our...

Distinction between Conscious and Nonconscious Processings

During sleep and deep general anesthesia, the subject is nonconscious with the notable, though limited, recall of the dreaming episodes. Even when awake, alert subjects may not be aware that they are carrying on intense nonconscious processing. Particular experimental evidence in favor of nonconscious processing (among many others) is the phenomenon of semantic priming (Dehaene, Naccache et al. 1998 review in Dehaene and Naccache 2001). Visual words, when flashed briefly before a masking...

Kc

Figure 10.5 Decoding of periodic and synchronized PN input by mushroom body (MB) Kenyon cells (KCs). (a) Cellular and circuit mechanisms responsible for low KC response probability and high input specificity. At each oscillation cycle, each KC receives a volley of excitatory PN inputs (E) from the large subset of PNs to which it is connected. The correspondence between the set of anatomical PN inputs to a KC and the PN activity vector at that time determines the level of depolarization ofthat...

Within Columns Vertical

The issue of whether or not there is a canonical microcircuit in the neocortex is of the utmost importance. The possibility of a common transfer function performed on any cortical input could be the equivalent of a DNAhelix model ofthe brain. As conceptualized earlier, the canonical microcircuit hypothesis can be articulated as the existence of a common single operator (or transfer function) of cortical function, one which would be similar in different cortical regions and in different species....

Dopaminergic Modulation Of The Intrinsic Properties Of Medium Spiny Neurons

The now classical model of dopamine action in the striatum was originally advanced by Albin, Penney, and Young (1989) over a decade ago. In this model, activation of D1 receptors excites neurons of the direct striatonigral pathway, whereas activation of D2 receptors inhibits medium spiny neurons of the indirect striatopallidal pathway. The evidence for this model came almost entirely from indirect measures of neuronal activity (e.g., alterations in gene expression, glucose utilization). We now...

Functional Microstates in the Human Brain

Thus far, our discussion has been limited to the dynamics observed in the membrane potential of a single cell, or averaged across a cortical column extension, through optical recording with a spatial precision of 50-100 m. Synchronicity and oscillatory behavior, however, is often more easily detected when averaging over larger spatial scales and using macroprobes, such as local-field potential and EEG. The term functional microstate is used to describe a particular, but very stable, empirical...

Cholinergic Modulation Of The Intrinsic Properties Of Medium Spiny Neurons

M1 and M4 Receptor Activation Increases Medium Spiny Neurons Excitability Both striatopallidal and striatonigral neurons express Mj and M4 receptors Hersch et al. 1994 Yan et al. 2001 . Mj receptors are expressed at uniformly high levels whereas M4 receptor mRNA is somewhat higher in striatonigral neurons. Mj receptors are Gq and PLC 3 linked. PLC activation results in the metabolism of PIP2 and the production of IP3 and DAG. The depletion of membrane PIP2 leads to a decrement in the open...

Dahlem Workshop Reports

After the workshop, attention is directed toward the necessity of communicating the perspectives and ideas gained to a wider audience. Atwo-tier review process guides the revision of the background papers, and discussion continues to finalize the group reports. The chapters are carefully edited to highlight the perspectives, controversies, gaps in knowledge, and future research directions. The publication of the workshop results in book form completes the process of a Dahlem Workshop, as it...

List of Participants

Hagai Bergman Dept. of Physiology and the Interdisciplinary Center for Neural Computation, The Hebrew University, P.O. Box 12272, Jerusalem 91120, Israel Basal ganglia and movement disorders neural networks and learning theory Maria Blatow Abt. Klinische Neurobiologie, Neurologische Universit tsklinik, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany Interneuronal networks synaptic plasticity J. Paul Bolam MRC Anatomical Neuropharmacology Unit, Mansfield Road, Oxford OX1 3TH, U.K....