Reciprocal interaction model

The existence of such an interaction was first proposed by Hobson et al. (1975) in the form of their Reciprocal Interaction Model According to these authors, the REM-OFF neurons in the LC are inhibitory to the REM-ON neuronal population, whereas the REM-ON neurons exert an excitatory effect on the LC REM-OFF neurons. Cessation of neuronal activity of the LC neurons during REM sleep thus results in the withdrawal of the tonic inhibition from the REM-ON neurons,... 

The generation of the NREM-REM cycle is explained by a reciprocal interaction model based on anatomical and physiological data and first proposed... 

The reciprocal interaction models on the NREM and REM sleep cycle (44) evolved from neurophysiological data obtained in animals. It is postulated that NREM-REM sleep cycle is caused by the reciprocal interaction of two neuronal systems in the brain stem with self-excitatory and self-inhibitory connections. For further details, recent monographs on sleep medicine should be consulted (45-47). 

The reciprocal lattice model as derived above is the basis for many different variants. For simplicity we have assumed the interactions between the next nearest neighbours A+ -B+ andC- I) to be independent of composition, even though experiments have shown that this is often not the case. It is relatively simple to introduce parameters which allow the interaction energy, for example between A+ and B+, to depend on the concentration of C and D [14], One may also include other terms that take into account excess enthalpies that are asymmetric with regard to composition and the effects of temperature and pressure. 

Let us consider a (2A + l)-degrees-of-freedom oscillator system (A is a nonnegative integer), whose Hamiltonian is given by a -interaction model truncated in reciprocal space (< )4 MTRS) ... 

It is interesting to note that all three mechanisms contributing to the attractive van der Waals interactions vary as the reciprocal of the separation distance to the sixth power. It is for this reason that the Lennard-Jones potential has been extensively used to model van der Waals forces. 

I2H2O as a function of the reciprocal temperature. The points are data obtained from fits of the Mdssbauer spectra (Fig. 6.6). The broken curve is a fit to the Einstein model for a Raman process. The dotted curve corresponds to a contribution from a direct process due to interactions between the electronic spins and low-energy phonons associated with critical fluctuations near the phase transition temperature. (Reprinted with permission from [32] copyright 1979 by the Institute of Physics)... 

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