Metabolic and behavioral response in rats treated with amphetamine chronically with and without challenge

Chronic amphetamine (AMPH) treatment may cause behavioral sensitization in animals and can be used as an animal model of psychosis. The aim of the study was to check the behavioral and metabolic response in this animal model. In rats pretreated with normal saline (NS) or AMPH, with or without AMPH challenge, the [14C]deoxyglucose method was employed to check the metabolic changes in 42 regions. Behavioral testing was performed in rats with the same treatment. The results showed that after challenge with AMPH, glucose utilization was enhanced in most of the regions investigated. However, metabolic enhancement of the AMPH-pretreated group was lower in the caudate nucleus when compared with that of the NS-pretreated group though the stereotypy rating was higher in the former. Dissociation between the metabolic enhancement and behavioral response was noted. Furthermore, more significant differences between the two pretreated conditions of glucose utilization were found with challenge than without challenge. Further evaluation using procedures which include advanced techniques can be applied in further investigation.

Dose-dependent effects of chronic amphetamine administration in local cerebral glucose utilization in rat

The daily dose of amphetamine pretreatment may affect the development of behavioral-sensitized patterns in rodents and amphetamine psychosis in humans. This experiment investigated the regional cerebral metabolic changes in rats after pretreatment with different doses of amphetamine by the 2-[14C]deoxyglucose method. Rates of local cerebral glucose utilization were examined in 37 regions of the rat brain. The result showed generally maximal metabolic augmentation in the 5.0 mg/kg group instead of in the 1.0 or the 10.0 mg/kg groups. Behavioral testing using motor activity cages in rats with the same regimen found no difference among groups. The findings demonstrate that there might be a window effect by daily amphetamine dose on the development of drug dependence and amphetamine psychosis. It was suggested that the 2(-)[14C]deoxyglucose method could be used for further study of animal models of amphetamine psychosis.

Short-term kinetics of the humoral anti-C1q response in SLE using the ELISPOT method: fast decline in production in response to steroids

Twenty four systemic lupus erythaematosus patients and 17 patients with other diagnoses were investigated regarding the presence of cells producing C1q reactive antibodies in peripheral blood mononuclear cells using the ELISPOT technique. These results were then compared with parallel serum levels of C1q reactive antibodies. Current production of anti-C1q was almost entirely confined to the systemic lupus erythaematosus group. Longitudinal analysis of anti-C1q ELISPOT positive patients showed rapid changes in the number of anti-C1q producing cells, but only slowly changing serum levels of the corresponding antibodies in response to glucocorticoids. In one systemic lupus erythaematosus patient prednisolone treatment had a selective effect on this autoantibody production, as the production of anti-C1q spot forming cells rapidly dropped to zero, at the same time as the number of total spot-forming cells showed only less change. In another patient, self-limiting connective tissue disease was associated with temporal occurrence of IgM anti-C1q. We believe, from these data, that the ELISPOT method for determination of current antibody production may be of particular value in longitudinal evaluation of disease course and therapeutic effects in systemic lupus erythaematosus and other rheumatic diseases.

Spectroscopic properties of desulfoferrodoxin from Desulfovibrio desulfuricans (ATCC 27774)

Desulfoferrodoxin, a non-heme iron protein, was purified previously from extracts of Desulfovibrio desulfuricans (ATCC 27774) (Moura, I., Tavares, P., Moura, J. J. G., Ravi, N., Huynh, B. H., Liu, M.-Y., and LeGall, J. (1990) J. Biol. Chem. 265, 21596-21602). The as-isolated protein displays a pink color (pink form) and contains two mononuclear iron sites in different oxidation states: a ferric site (center I) with a distorted tetrahedral sulfur coordination similar to that found in desulforedoxin from Desulfovibrio gigas and a ferrous site (center II) octahedrally coordinated with predominantly nitrogen/oxygen-containing ligands. A new form of desulfoferrodoxin which displays a gray color (gray form) has now been purified. Optical, electron paramagnetic resonance (EPR), and Mössbauer data of the gray desulfoferrodoxin indicate that both iron centers are in the high-spin ferric states. In addition to the EPR signals originating from center I at g = 7.7, 5.7, 4.1, and 1.8, the gray form of desulfoferrodoxin exhibits a signal at g = 4.3 and a shoulder at g = 9.6, indicating a high-spin ferric state with E/D approximately 1/3 for the oxidized center II. Redox titrations of the gray form of the protein monitored by optical spectroscopy indicate midpoint potentials of +4 +/- 10 and +240 +/- 10 mV for centers I and II, respectively. Mössbauer spectra of the gray form of the protein are consistent with the EPR finding that both centers are high-spin ferric and can be analyzed in terms of the EPR-determined spin Hamiltonian parameters. The Mössbauer parameters for both the ferric and ferrous forms of center II are indicative of a mononuclear high spin iron site with octahedral coordination and predominantly nitrogen/oxygen-containing ligands. Resonance Raman studies confirm the structural similarity of center I and the distorted tetrahedral FeS4 center in desulforedoxin and provide evidence for one or two cysteinyl-S ligands for center II. On the basis of the resonance Raman results, the 635 nm absorption band that is responsible for the gray color of the oxidized protein is assigned to a cysteinyl-S-->Fe(III) charge transfer transition localized on center II. The novel properties and possible function of center II are discussed in relation to those of mononuclear iron centers in other enzymes.

[Lysosomal enzyme activity of cultured fetal cells in Chinese and its clinical application]

Lysosomal storage diseases (LSD) are caused by deficient activity of specific lysosomal enzymes. Early diagnosis and selective termination is still the trend of therapy. The purpose of this study was to establish an assay system and investigate the reference range of lysosomal enzyme activity of cultured fetal cells in the Chinese population. Seventy amniotic fluid and 9 chorionic villi samples were collected and cultured in this study. Enzyme activity assay was done by synthesized 4-Mu-binded substrates. The activity was expressed as nmol/mg protein/hour. In cultured amniotic cells, the results showed 14-138 of alpha-glucosidase, 8-133 of alpha-galactosidase, 32-470 of alpha-mannosidase, 101-1121 of alpha-fucosidase, 106-1321 of beta-galactosidase, 15-268 of beta-glucosidase, 11-279 of beta-glucuronidase, 101-1193 of Hexosaminidase A, and 886-6204 of N-acetyl-alpha-glucosaminidase. In cultured chorionic villi samples, it showed 22-335 of alpha-glucosidase, 31-230 of alpha-galactosidase, 47-250 of alpha-mannosidase, 35-218 of alpha-fucosidase, 49-934 of beta-galactosidase, 34-329, of beta-glucosidase, 57-379 of beta-glucuronidase, and 328-3412 of Hexosaminidase A. The enzyme activity was not correlated with the gestation age when sample was obtained. Furthermore, there was no statistical significance among the range of amniotic cells, chorionic villi samples, skin fibroblasts and peripheral leukocytes for each enzyme studied. It is suggested that the synthesis of lysosomal enzymes has been mature since the early fetal state, and the samples obtained as early as 8 weeks of gestation age can be used for early diagnosis of lysosomal storage diseases.

Effects of tetrandrine on functions and ultrastructure of alveolar macrophages in smoke inhalation-injured rabbits

A rabbit model with severe smoke inhalation injury was used to explore the effects of tetandrine (Tet) on the release of inflammatory mediators and the level of [Ca2+]i in alveolar macrophages (AM) as well as on the ultrastructural changes. It was found that Tet reduced the number of white blood cells (WBC) in bronchoalveolar lavage fluid, inhibited the release of LTB4 and O2-. from AM, and increased the [Ca2+]i in AM. The changes in size, pseudopod, and lysosome evacuation in AM treated with Tet were smaller than those in the AM from the untreated. These results suggest that Tet may alleviate the pulmonary injury through inhibiting the activation of AM.

[Bone metabolism and Chinese medicinal treatment of menopausal osteoporosis]

48 perimenopausal women were divided into premenopausal (PrM) and postmenopausal (PoM) groups, which were sub-divided into Chinese medicinal herbs (CM) and DES treatment groups, and 12 middle aged women were served as control. E0, E2, T, GH, Ca, P and ALP in the serum and the ratio of Ca/Cr in fasting urine as well as the BMD of right radius was measured. Results showed: The E0, E2 of the PoM were significantly lower than those of the PrM and control groups (P < 0.05, P < 0.01), with no remarkable difference in GH; the T value of PoM was lower than that of control (P < 0.01). Serum Ca and ALP and the ratio of Ca/Cr in fasting urine of the PoM were much higher than those of the control (P < 0.01); the serum Ca and urinary Ca/Cr of the PrM were higher than those of the control (P < 0.05, P < 0.01 respectively). The BMD value of the radius of both PoM and PrM groups were much lower than that of control (P < 0.01), the BMD of the PoM was lower than that of PrM (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of tetrandrine on production of leukotriene B4 and thromboxane B2 in rabbit blood

The effects of tetrandrine (Tet) on the production of 2 major metabolites of arachidonic acid (AA), the leukotriene B4 (LTB4) and the thromboxane B2 (TXB2) in rabbit whole blood were investigated by reversed phase high pressure liquid chromatography (HPLC) and radioimmunoassay (RIA), respectively. After incubation with different doses of Tet for 15 min in vitro, the production of LTB4 and TXB2 by rabbit whole blood stimulated with calcimycin (20 mumol.L-1) was inhibited in a dose-dependent manner, with IC50 value of 17.8 +/- 8.6 and 17.7 +/- 9.2 mumol.L-1, respectively. In the presence of exogenous AA, the inhibitory effects of Tet were markedly lessened. The effects of Tet were much like those of calmodulin (CaM) antagonist fluphenazine (Flu). Dexamethasone (Dex) also inhibited the production of LTB4 and TXB2 when incubated with rabbit whole blood for 60 min. Tet iv 10 mg.kg-1 also inhibited the production of LTB4 and TXB2 in rabbit whole blood stimulated with calcimycin. These results suggest that Tet may be an antagonist of CaM, thus suppressing the release of AA which was catalyzed by CaM dependent phospholipase A2 (PLA2) from the membrane phospholipids of blood cells.

Demonstration of type III collagen in the dentin of mice

It has been reported that, although type III collagen is present in human dentin where there is dentinogenesis imperfecta and in reparative dentin, it is absent in normal dentin. In a preliminary study, however, we observed evidence showing that small amounts of fibers showing positive labeling for type III collagen are present in the molars of normal mice. In the present study, in order to localize type III in normal dentin, immunofluorescent and immunoelectron microscopic examinations of the molars of normal mice were carried out using affinity-purified antibodies to mouse type III and type I collagen. The fibers positive for type III collagen were much more frequently observed in the root than in the crown. These fibers ran in peritubular dentin or near that in parallel to them. The incidence of the existence of dentinal tubules associated with type III collagen-positive fibrils either in or near peritubular dentin was low. These fibrils positive for type III collagen showed a clear cross-banding. In dentinal tubules, unusual collagen aggregations, segment long-spacing-like and fibrous long-spacing-like structures which were intensively stained for type I collagen but weakly so for type III collagen were seldom observed. Type III collagen-positive fibers often extended towards the pulp beyond the odontoblast layer, suggesting that these fibers were produced, at least partly, by the pulp cells.

Inhibitory effects of tetrandrine on Bay k 8644-stimulated contraction of isolated rabbit aortic strips

In the presence of KCl 19 mmol.L-1, calcium agonist Bay k 8644 0.47 mumol.L-1 elicited a strong contraction of isolated rabbit aortic strips, and this contraction was concentration-dependently inhibited by tetrandrine; but this antagonism was noncompetitive. Calcium ionophore calcimycin evoked contraction was markedly depressed by tetrandrine. The results suggested that tetrandrine might not only inhibit transmembrane influx of calcium via potential-dependent channels but also interfere with other processes related to calcium.

Distribution of type I and type III collagen in the developing periodontal ligament of mice

In order to localize type I and type III collagen in developing periodontal ligament, immunofluorescent and immunoelectron microscopic examinations were undertaken. The materials used were the maxillary molars of CF1 mice, 13 days to 6 months old. The antibodies used were monospecific polyclonal antibodies against type I or type III collagen raised in rabbits or guinea pigs, respectively. Single- and double-staining methods were employed in immunofluorescent as well as immunoelectron microscopic examinations. In immunofluorescent examinations, during the development of the periodontal ligament, periodontal fibers showed intense and homogenous staining for both type I and type III collagen; while Sharpey's fibers in the alveolar bone showed a heterogenous staining in cross and longitudinal sections for both types of collagen. In immunoelectron microscopic examinations, fibrils of periodontal fibers showed positive staining for type I and type III collagen simultaneously and had characteristic cross-banding and had a large diameter (ranging 40 approximately 80 nm) which remained constant during development. Sharpey's fibers in the alveolar bone or in the cementum showed the same staining pattern as the periodontal fibers, except for an afibrillar area which showed negative staining for both type I and type III collagen. The results obtained suggest that periodontal fibers and Sharpey's fibers consist of cofibrils of at least type I and type III collagen.

[Relaxant effects of protopine on smooth muscles]

The relaxant effects of protopine (Pro) on smooth muscles were studied by recording isotonic contraction and radioimmunoassay. Pro relaxed the contraction of rabbit thoracic aorta, mesenteric artery, portal vein and guinea pig ileum and taenia colon induced by high K+ (70 mmol.L-1). Pro also inhibited the contraction of rabbit thoracic aorta, mesenteric artery, portal vein induced by NE (0.3 mumol.L-1) and guinea pig taenia colon induced by BaCl2 (1 mmol.L-1). Pro inhibited the intracellular Ca2+ release, but did not inhibit Ca2+ influx induced by NE. These results suggested that the smooth muscle relaxant mechanism of action of Pro may be the inhibition of intracellular Ca2+ release.

[Effects of tetrandrine on rabbit platelet aggregation, thromboxane A2 generation and calmodulin activity]

The effects of tetrandrine (Tet) on platelet aggregation and thromboxane A2 (TXA2) generation were studied in rabbit platelet-rich plasma (PRP) prepared by centrifugation. The effects of Tet on calmodulin activity in platelet extracts were also investigated by measuring calmodulin-sensitive phosphodiesterase activity. ADP, collagen or arachidonic acid (AA)-induced platelet aggregation was inhibited by Tet in a dose-dependent manner. TXA2 generation in PRP treated by Tet was markedly decreased in collagen-induced group, but was not altered in AA-induced group, suggesting that the release of AA from platelet phospholipids stimulated by collagen was blocked by Tet. Further experiments showed that the effects of Tet were related to its inhibition of calmodulin-dependent phosphodiesterase activity. There was evidence that the effects originated from its anti-calmodulin properties instead of its direct action on phosphodiesterase.

Behavior of monkeys during opiate withdrawal and locus coeruleus stimulation

The noradrenergic nucleus locus coeruleus (LC) has been implicated in morphine withdrawal. The behavioral effects of opiate antagonist-precipitated morphine withdrawal in chair-restrained Macaca arctoides were therefore compared with LC electrical field stimulation. Both continuous LC stimulation and administration of low doses of naloxone to morphine pellet implanted monkeys produced a significant increase in the same group of behaviors reported previously to follow activation of the LC, without significant increases in general activity or distress behaviors. Signs of autonomic hyperactivity and distress were observed at high doses of naloxone, but not during LC stimulation. Monkeys which had not received morphine treatment did not specifically increased during low intensity LC stimulation is also selectively increased during naloxone-precipitated morphine withdrawal. These data are consistent with and suggest a behavioral consequence of the interactions of opioids with the LC reported at the molecular, intracellular, and cellular level.

Effects of dexamethasone on electroacupuncture analgesia and central nervous system metabolism

Many reports have indicated that electro-acupuncture analgesia (EAA) was mediated by endorphins. Among them is B-endorphin which can be released from the anterior lobe of the pituitary. To examine the role of B-endorphin in EAA and observe CNS metabolic (functional) and behavioral effects of dexamethasone the present study employed the (14C) 2-deoxyglycose (2DG) method. Seventeen adult male Sprague-Dawley rats in five groups received the following different types of somesthetic stimulation to examine the local cerebral glucose utilization (LCGU) and tail-flick response latency: control group (N = 3), pain group (N = 4), EA group (N = 3), pain + EA group (N = 3; from another ongoing study) and dexamethasone group (N = 4). Dexamethasone reduced tail-flick response latency in response to electroacupuncture, and produced metabolic (functional) changes in a number of CNS structures implicated in electroacupuncture produced analgesia effects (some changes were statistically significant, many others were not). Specific brain structures exhibiting statistically significant changes (p less than 0.05) in LCGU when compared to the pain + EA group are: the parafascicular and habennlar nuclei of the thalamus and the posterior cingulate gyrus. In comparison of dexamethasone group with the other four experimental groups of rats, the following trend in LCGU changes was observed: pain + EA group greater than pain group = EA group = dexamethasone group greater than control group. In addition, dexamethasone had a sedative effect. The results suggest that dexamethasone is reducing EAA and having suppressive effects on CNS metabolism and behavior.

Nonoperative treatment of Hirschsprung's disease: a new approach

The approach of the combined traditional Chinese and modern medicinal treatment of Hirschsprung's disease has been applied in 90 cases. Long-term follow-up showed satisfactory results. Of these, 55 cases with a typical history, plus a positive ACHE and x-ray were selected for analysis and discussion, making an over all rate of 78.18%. This treatment is particularly useful for those babies under 1 year of age with a short narrow segment of the rectum. In addition, it would be a good trial procedure for those babies over 1 year old with mild symptoms and the narrow segment just beyond the sigmoidorectal junction.

Systemic penicillin as an experimental model of epilepsy

Systemic use of high-dose penicillin was studied in rats and cats to establish an experimental model of epilepsy. In rats, intraperitoneal injection of 2.5 to 5.0 million units/kg (MU/kg) penicillin was effective to induce spikes in 45.7 +/- 31.0 min (means +/- SD) and seizure in 71.5 +/- 38.4 min. In cats, intravenous administration of penicillin at 0.5 to 1.0 MU/kg induced spikes in 10.4 +/- 7.8 min and seizure in 32.2 +/- 19.8 min. Intraperitoneal use of penicillin at 1.0 to 2.0 MU/kg caused spikes in 24.0 +/- 18.4 min and seizure in 71.2 +/- 38.3 min. Pretreatment with intravenous isoniazid at 16.3 +/- 10.3 mg/kg significantly delayed the appearance of intravenous penicillin-induced spikes to 63.1 +/- 49.8 min or prevented the appearance of spikes and abolished the occurrence of seizures. Acupuncture at various points increased the penicillin-induced spikes and seizures.

The flushing response to alcohol use among Koreans and Taiwanese

Alcohol use, the existence of a flushing response to alcohol and the amount of alcohol required to evoke flushing were studied by questionnaire in 87 homeland Korean and 101 Taiwan Chinese families. SFs (slow flushers--flush after two or more drinks) and FFs (fast flushers--flush after one drink or less) were compared. Despite the similarity in the proportions of subjects who reported flushing, Koreans reported very heavy and Taiwanese very light alcohol use. The two groups differed substantially in the proportions of SFs and FFs. Five ethnic groups in Hawaii were compared with the Koreans and Taiwanese. It appears that fast flushing, but not slow flushing, leads to substantial decreases in alcohol use among all seven groups. The association of flushing type with the extent and duration of flushing and with the frequency of other alcohol-related symptoms may be dose-dependent. For both Koreans and Taiwanese, family resemblances in flushing are substantial but not supportive of the belief that flushing is dominant and results from the influence of a single autosomal gene pair. Of the large groups of subjects from whom data were obtained (Caucasians, Chinese, Filipinos, Hawaiians or part Hawaiians, and Japanese in Hawaii; homeland Koreans; and Taiwan Chinese), the Koreans and Taiwanese differ the most from one another in alcohol consumption. In summary, there is substantial diversity among groups frequently lumped together as "Mongoloid."

Acupuncture on experimental epilepsies

The therapeutic effect of acupuncture on epilepsies was evaluated in 4 experimental models. 24 acupuncture points were tried. In electroconvulsive threshold model, square wave electrical stimulus of 0.2 msec and 6 Hz was applied through a pair of cotton electrodes at the cornea of mice for 3 sec. The stimulus intensity to induce stun reaction of the mouse was compared. In 86 control animals, the stimulus threshold was 0.70 +/- 0.22 mA. In the acupuncture treated group (N = 80), the threshold was 0.75 +/- 0.14 mA. In maximal electroshock model, the stimulus parameters were 60 Hz, 0.4 sec and 75 mA. The tonic extensor response of the hindlimbs of the mice was observed. 75.7% of the 115 control mice and 77.5% of the 80 acupuncture treated mice were observed to have tonic extensor response. In the focal cortical penicillin model, penicillin was applied at the subpial space over the exposed cortex of 24 cats. After the appearance of repeated spikes in ECoG, acupuncture was performed. In 175 trials the interictal spikes were decreased in 16 times, increased in 82 times. In 99 trials during seizures, the ictal activity was decreased in 4 times, increased in 79 times. In the intravenous penicillin model, high dose penicillin (1,000,000-1,500,000 U/kg) was given to 20 cats. It induced repetitive spikes and frequently even seizure discharges in EEG. Acupuncture was then tried. In 192 instances, acupuncture reduced the spikes in 13, increased the spikes in 103 times. In 74 trials during seizures, the ictal activity was suppressed in 4 times and aggravated in 66 times.(ABSTRACT TRUNCATED AT 250 WORDS)

The primate locus coeruleus and effects of clonidine on opiate withdrawal

Studies of nonhuman primates suggested that the noradrenergic locus coeruleus (LC) may be involved as part of the neural substrate for a brain alarm function which includes attentiveness, arousal, anxiety, fear, terror, and the physiological correlates of these states. The studies compared the effects of electrical activation of tiny electrodes in the locus coeruleus with the effects of other agents and conditions which increased or decreased LC activity. The results suggested that the activation of the LC system is prevented by endogenous morphine-like substances and by opiates and that the opiate withdrawal syndrome is due to activation of this LC-noradrenergic system. Clonidine, which in low doses suppressed noradrenergic and LC activity, was therefore postulated to suppress opiate withdrawal signs and symptoms. The confirmation of this hypothesis in rats, monkeys and human subjects has added to the understanding of the mechanisms of opiate action and withdrawal.

D-Amphetamine at low doses suppresses noradrenergic functions

This study examined the effects of d-amphetamine on the firing rate of hippocampal cells which had been shown to have an inhibitory, noradrenergic input from the nucleus locus coeruleus (LC). d-Amphetamine at low doses of 0.1 mg/kg i.v. or 0.5 mg/kg i.p. increased the firing rates of these cells. With higher doses of d-amphetamine, both increases and decreases in the firing rates of hippocampal cells were observed. These differential effects on the firing rate of hippocampal cells were statistically significant (x2 = 13.32, d.f. = 3, P less than 0.01). The increased firing rate of hippocampal cells produced by the low doses of d-amphetamine was blocked by a prior destruction of the LC indicating that the drug effect was mediated by LC neurons. d-Amphetamine also significantly attenuated the decrement in the firing rates of hippocampal cells produced by LC stimulation (P less than 0.01). These results suggest that low doses of d-amphetamine suppress rather than enhance the actions os norepinephrine.

The time course of noradrenergic pre- and postsynaptic activity during chronic desipramine treatment

The firing of hippocampal cells was studied in rats treated with desipramine 10 mg/kg per day i.p. for various periods of time. These cells were neurophysiologically identified to be noradrenergic postsynaptic by their decreased firing during stimulation of the locus coeruleus (LC). While desipramine given for 1 day produced no change, the drug given for 7, 14, and 21 days produced a 20%, 38% and 89% increase, respectively; only the last increase reached a statistical significance. This time course closely resembles that of the therapeutic action of the drug in depressed patients. Desipramine also altered the firing of norepinephrine-containing cells in the LC. While desipramine given for 1 day produced no change, the drug given for 7, 14 and 21 days produced a 12%, 29% and 34% decrease, respectively; only the last two decrements reached a statistical significance. This time course resembles that of the change in firing of hippocampal cells. Based on this and other data it is suggested that the decrease in the firing of LC cells plays a major role in the increased firing of hippocampal cells obtained after desipramine treatment.

Reported lactose tolerance of members of various racial/ethnic groups in Hawaii and Asia

Subjects from various racial/ethnic groups in Hawaii and homeland Chinese, Japanese, and Koreans reported on their milk drinking in childhood and adulthood, as well as on whether or not milk drinking produced symptoms of intolerance. Intolerance was comparatively infrequent in all groups, although significant differences existed between groups in the frequency with which they manifested symptoms and in discomfort scores. Differences between Hawaiian subjects of Asian ancestry and homeland Asians in the frequency of reported symptoms, in mean discomfort scores, and in amount of milk needed to produce symptoms, as well as the high proportion of symptomatology among Hapa-Haoles (persons of Caucasian and Oriental ancestry) and other data reported herein, are not supportive of the usual genetic explanation of lactose tolerance and are supportive of the belief that dietary practice influences tolerance.

Stimulation of the dorsal noradrenergic dundle and field potentials in the locus coeruleus

Field potentials were recorded from the locus coeruleus following electrical stimulation of the rat midbrain. Activation of a discrete area situated ventrolateral to the central gray evoked long-latency potentials in the locus coeruleus while stimulation of other midbrain sites did not. Damage to this discrete area resulted in a depletion of norepinephrine in the cerebral cortex suggesting that it is a segment of the dorsal noradrenergic bundle arising from the locus coeruleus.

Unit activities in the hypothalamus and midbrain during stimulation of hypothalamic attack sites

Unit activity in the hypothalamus and midbrain of unanesthetized cats was studied during electrical stimulation of the hypothalamus at sites that induced attack and at other comparable sites from which attack was not induced. The changes in the firing of units at distances from 0.7 to 1.9 mm from the site of stimulation were similar to those of units at distances from 2.0 to 5.2 mm. Although stimulation in general affected a majority of units, resulting in increases rather than in decreases of firing rates, and produced similar patterns of unit activity, stimulation at sites that induced attack affected more units, produced a greater change in unit activity and markedly increased firing rates in the lateral hypothalamus and the dorsal part of the midbrain.