Electroencephalographic correlates of learning in subcortical and cortical structures

Reverberation, storage, and postsynaptic propagation of memories during sleep

“…Despite early insight (Jenkins and Dallenbach 1924), it was not until the 1970s that science began to recognize the key role of sleep in memory consolidation. The main findings supporting this view are the detrimental effects of sleep deprivation on learning (Pearlman 1969(Pearlman , 1973Leconte and Bloch 1970;Fishbein 1971;Pearlman and Becker 1974;Linden et al 1975;Shiromani et al 1979;Smith and Butler 1982;Smith and Kelly 1988;Smith and MacNeill 1993;Karni et al 1994;Smith and Rose 1996;Stickgold et al 2000a;Walker et al 2002;Maquet et al 2003;Mednick et al 2003), the improved memory retention in rats when REM sleep is enhanced (Wetzel et al 2003), the increase in sleep amounts following memory acquisition (Lucero 1970;Leconte and Hennevin 1971;Fishbein et al 1974;Smith et al 1974Smith et al , 1980Smith andLapp 1986, 1991;Smith and Wong 1991), and the fact that theta rhythm, a learning-related (Adey et al 1960;Elazar and Adey 1967;Landfield et al 1972;Bennett 1973;Bennett et al 1973;Winson 1978;Sederberg et al 2003) hippocampal oscillation typical of high arousal (Green and Arduini 1954;Brown 1968;Sainsbury 1970;Harper 1971;<...>…”

Similar effects of medial supramammillary or systemic injection of chlordiazepoxide on both theta frequency and fixed-interval responding

“…In the rat, theta is prominent during voluntary movements (Slawinska & Kasicki, 1998;Vanderwolf, 1969) and has been associated with basic psychological functions, such as arousal (Green & Arduini, 1954), orienting (Grastyan, Lissak, Madarasz, & Donhoffer, 1959), attention (Bennett, 1975), sensorimotor processing (Bland, 1986), and sensory inhibition (Sainsbury, 1998). Numerous studies have also linked theta with higher order cognitive processes (AmmassariTeule, Maho, & Sara, 1991;Destrade, 1982;Elazar & Adey, 1967;Givens & Olton, 1994;Grastyan, Karmos, Vereczkey, & Kellenyi, 1966;Landfield, 1977;Landfield, McGaugh, & Tusa, 1972;Wetzel, Ott, & Matthies, 1977;Winson, 1978), and with emotion (Graeff, Quintero, & Gray, 1980;Gray, 1972;Montoya, Heynan, Faris, & Sainsbury, 1989;Snape, Grigoryan, Sinden, & Gray, 1996;Williams & Gray, 1996). What is often common to these latter two perspectives is the idea that the specific frequency of theta is critical for the behavioral output.…”

Area in the Rat Brain Producing Rhythmical Slow Activity after Chemical Stimulation

“…The input of the nucleus of the diagonal bands of Broca to the hippo campus has been described anatomically [4] and physiologically [5,25], This study seems to suggest that there are fairly localized areas within the septal diagonal bands of Broca which project separately to ventral and dorsal hippocampal areas. The area in the dorsal hippocampus related to RSA production appeared to lie within the lower rim of the nucleus, whereas the tip of the nucleus influenced both dorsal and ventral hippo campal areas.…”

“…Hippocampal rhythmical slow activity (RSA) in the rat is defined as regular slow-wave 3-to 10-Hz electrical activity and has been correlated with a variety of functions including arousal [7], voluntary movement [29,30], synchronicity of rhythmical behavior [17], the orienting reflex [14,21], and attention and learning [5]. The rhythm can be induced by arecoline [4], but is abolished by intravenous atropine [1,26] or scopo lamine [24,25].…”