Lateral lemniscus

Tougaard, J., Casseday, J. H. and Covey, E. (1998). Arctiid moths and bat echolocation broad band clicks interfere with neural responses to auditory stimuli in the nuclei of the lateral lemniscus of the big brown bat. Journal of Comparative Physiology A 182 203-215. 

This interpretation finds support in systematic studies of responses from brainstem nuclei following successive coagulative lesion production in the auditory loci (1 7). The effect of brainstem lesions on electrical potentials recorded from the superior olivary (SO) nucleus in response to microwave pulse stimulation is shown in Figure 3. Lesions in proximal nuclei (inferior colliculus, IC and lateral lemniscus, LL) had negligible influence on the response recorded from superior olivary nucleus. The response, however, disappeared after a lesion was made in its nucleus, thus, confirming the peripheral nature of the primary site of transduction. 

Refer to Ruigrok and Celia (1995) for a general description of these structures. Within what has been previously called the pararubral area (Ruigrok and Celia, 1995) there is a circumscribed cell group which we called the pararubral nucleus. We have named the large cells below the minimus nucleus and above the lateral lemniscus the epilemniscal nucleus (Paxinos et ai, in press [b]). 

VLH ventrolateral hypothalamic nucleus 22-24, 82-83, 93 VLL ventral nucleus of the lateral lemniscus 50-53, 83-85, 90-98 VLPAG ventrolateral periaqueductal gray 50-54, 81 VLPO ventrolateral preoptic nucleus 19-21, 82 VLTg ventrolateral tegmental area 52-53, 82-83, 91-93 VM ventromedial thalamic nucleus 26-35, 81-83, 98-102 VMH ventromedial hypothalamic nucleus 80-81, 90-92 VMHA ventromedial hypothalamic nucleus, anterior part 28 VMHC ventromedial hypothalamic nucleus, central part 29-34 VMHDM ventromedial hypothalamic nucleus, dorsomedial part 29-... 

Fig. 180. Schematic illustration of the result of D-[ H]aspartate injection into lobules IV and V of the cerebellum of the rat. In the sketches of the cerebellar sections, retrogradely labelled axons and axon collaterals are indicated by lines and dots. Filled dots in the olives indicate the location of labelled cells. Retrograde labelling in cells of the inferior olive is also illustrated in more detail in the diagrams on the right. BP = brachium pontis DAO = dorsal acessory olive DN = Deiters nucleus FN = fastigial nucleus LL = lateral lemniscus LLV = ventral nucleus of the lateral lemniscusw MAO = medial accessory olive OI = inferior olive OS = superior olive PN = pontine nuclei PO = principal olive RB = restiform body I-X lobules I-X. Wiklund et al. (1984).

Fig. 1. Records of potentials in the right lateral lemniscus and right auditory cortex evoked by presentation of 30 ms tonal pips (600 Hz) under sound proof and distractive conditions before and after 0.5 mg/kg N-methyl-3-piperidyl benzilate.

Fig. 2. Effect of N-methyl-3-piperidyl benzilate and LSD-25 on the amplitude of potentials evoked in the lateral lemniscus of the cat in relation to the environmental conditions. Each point on the graphs represents the mean amplitude of 4 individual potentials evoked every 20 s by 30 ms...

Fig. 3. Histograms showing effects of drugs on the amplitude of potentials evoked in the lateral lemniscus of cats in relation to the environmental conditions.

The effects of 3 anticholinergic drugs (atropine, hyoscine and N-methyl-3-piperidyl benzilate) have been studied on the EEG and potentials evoked in the specific auditory pathway (lateral lemniscus and auditory cortex) in cats subjected to different environmental conditions and trained to a conditioned avoidance response. 

Fluctuation in amplitude of potentials evoked in the lateral lemniscus appeared to be related to the distractability or attentiveness of the animal. After administration of anticholinergic drugs fluctuation in amplitude of potentials recorded under dis-tractive conditions was smaller than in untreated animals subjected to similar environmental conditions LSD-25 increased the degree of fluctuation. 

The central auditory system consists of the cochlear nuclei groups of brainstem nuclei including the superior olivary complex (SOC), nuclei of the lateral lemniscus (LL), and inferior colliculus (1C) and the auditory thalamocortical system consisting of the medial geniculate in the thalamus and multiple areas of the cerebral cortex. Figure 5.4 schematically indicates the nuclear levels and pathways. Efferent pathways are not shown. Page constraints prevent us from providing uniform detail for all levels of the auditory system. 

The LL consists of ascending axons from the CN and LSO. The nuclei of the lateral lemniscus (NLL) lie within this tract, and some, such as the dorsal nucleus LL (DNLL), are known to process binaural information [Burger and Poliak, 2001], but less is known about these nuclei as a group than others, partially due to their relative inaccessibility. 

Burger R.M. and Poliak G.D. (2001). Reversible inactivation of the dorsal nucleus of the lateral lemniscus reveals its role in the processing of multiple sound sources in the inferior colliculus of bats. /. Neurosci. 21 4830-4843. 

Fig. 3 Example ABR waveform with corresponding auditory pathway locations. Waves I and II represent activity in the auditory nerve, wave III represents activity in the cochlear nucleus, wave IV represents activity in the superior olivary complex, and wave V represents activity in the lateral lemniscus...

NLL (nuclei of the lateral lemniscus), 5-11 Nobili, R., 63-2, 63-9 Noble, D., 22-15-22-16 Nonablative treatment, 29-9 Non-aliphatic polyesters type... 

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