Median digitalisoituminen ja yhdistetty tieto

Esitys Kansalliskirjaston Finto-palvelun ja arkistosektorin KDK-yhteistyöverkoston järjestämässä seminaarissa: Linkity! Kohti yhteentoimivaa metatietoa 3.9.2014.

Normal median near nerve potential

In routine studies of sensory nerve conduction, only fibers e7 µm in diameter are analyzed. The late components which originate from thinner fibers are not detected. This explains why a normal sensory action potential (SAP) may be recorded in patients with peripheral neuropathies and sensory loss. In the present study we investigated the late component of the median SAP with a near nerve needle electrode technique in 14 normal volunteers (7 men and 7 women), aged 34.5 ± 14.8 years. The stimulus consisted of rectangular pulses of 0.2-ms duration at a frequency of 1 Hz with an intensity at least 6 times greater than the threshold value for the main component. Five hundred to 2000 sweep averagings were performed. The duration of analysis was 40 or 50 ms and the wave analysis frequency was 200 (-6 dB/oct) to 3000 Hz (-12 dB/oct). We used an apparatus with a two-channel amplifier system, 200 MW or more of entry impedance and a noise level of 0.7 µVrms or less. The main component mean amplitude, conduction velocity and latency and the late component mean amplitude, conduction velocity and latency were respectively (mean ± SD): 26.5 ± 5.42 µV, 56.8 ± 5.42 m/s, 3.01 ± 0.31 ms, 0.12 ± 0.04 µV, 16.4 ± 2.95 m/s and 10.6 ± 2.48 ms. More sophisticated equipment has an internal noise of 0.6 µVrms. These data demonstrate that the technique can now be employed to study thin fiber neuropathies, like in leprosy, using commercial electromyographs, even in non-academic practices

Excitotoxic median raphe lesions aggravate working memory storage performance deficits caused by scopolamine infusion into the dentate gyrus of the hippocampus in the inhibitory avoidance task in rats

The interactions between the median raphe nucleus (MRN) serotonergic system and the septohippocampal muscarinic cholinergic system in the modulation of immediate working memory storage performance were investigated. Rats with sham or ibotenic acid lesions of the MRN were bilaterally implanted with cannulae in the dentate gyrus of the hippocampus and tested in a light/dark step-through inhibitory avoidance task in which response latency to enter the dark compartment immediately after the shock served as a measure of immediate working memory storage. MRN lesion per se did not alter response latency. Post-training intrahippocampal scopolamine infusion (2 and 4 µg/side) produced a more marked reduction in response latencies in the lesioned animals compared to the sham-lesioned rats. Results suggest that the immediate working memory storage performance is modulated by synergistic interactions between serotonergic projections of the MRN and the muscarinic cholinergic system of the hippocampus.

Pervotuotteita median markkinoilla

Kirjallisuusarvostelu

Role of nitric oxide of the median preoptic nucleus (MnPO) in the alterations of salivary flow, arterial pressure and heart rate induced by injection of pilocarpine into the MnPO and intraperitoneally

We investigated the effect of L-NAME, a nitric oxide (NO) inhibitor and sodium nitroprusside (SNP), an NO-donating agent, on pilocarpine-induced alterations in salivary flow, mean arterial blood pressure (MAP) and heart rate (HR) in rats. Male Holtzman rats (250-300 g) were implanted with a stainless steel cannula directly into the median preoptic nucleus (MnPO). Pilocarpine (10, 20, 40, 80, 160 µg) injected into the MnPO induced an increase in salivary secretion (P<0.01). Pilocarpine (1, 2, 4, 8, 16 mg/kg) ip also increased salivary secretion (P<0.01). Injection of L-NAME (40 µg) into the MnPO prior to pilocarpine (10, 20, 40, 80, 160 µg) injected into the MnPO or ip (1, 2, 4, 8, 16 mg/kg) increased salivary secretion (P<0.01). SNP (30 µg) injected into the MnPO or ip prior to pilocarpine attenuated salivary secretion (P<0.01). Pilocarpine (40 µg) injection into the MnPO increased MAP and decreased HR (P<0.01). Pilocarpine (4 mg/kg body weight) ip produced a decrease in MAP and an increase in HR (P<0.01). Injection of L-NAME (40 µg) into the MnPO prior to pilocarpine potentiated the increase in MAP and reduced HR (P<0.01). SNP (30 µg) injected into the MnPO prior to pilocarpine attenuated (100%) the effect of pilocarpine on MAP, with no effect on HR. Administration of L-NAME (40 µg) into the MnPO potentiated the effect of pilocarpine injected ip. SNP (30 µg) injected into the MnPO attenuated the effect of ip pilocarpine on MAP and HR. The present study suggests that in the rat MnPO 1) NO is important for the effects of pilocarpine on salivary flow, and 2) pilocarpine interferes with blood pressure and HR (side effects of pilocarpine), that is attenuated by NO.

The compulsive-like aspect of the head dipping emission in rats with chronic electrolytic lesion in the area of the median raphe nucleus

Head dipping (HD) is a behavioral pattern considered to have a risk assessment or an exploratory role and is used as a complementary parameter to evaluate anxiety in experimental animals. Since rats with electrolytic lesion in the area of the median raphe nucleus displayed high frequencies of HD in a previous study, the present investigation was undertaken to confirm this observation and to determine its anxiety-related origin. HD episodes were counted in adult male Wistar rats (270-350 g) with electrolytic lesion (N = 11) and sham-lesioned controls (N = 12). When HD was measured for 60 min on an elevated open platform, lesioned rats emitted 13 times more HD than controls (264.7 ± 93.3 vs 20.3 ± 7.6 episodes), with the difference being statistically significant (P < 0.05). HD counts during 10-min sessions held 7, 14, 21, 27, and 63 days after lesion showed significantly higher means (range: 28.14 ± 5.38 to 62.85 ± 9.48) compared to sham-lesioned controls (range: 7.37 ± 1.13 to 8.5 ± 1.45). Normal rats stepped down into their home cages when the vertical distance between them and the cage was short (16 cm), and the step-down latencies increased with increasing depths (36.7 ± 7.92 to 185.87 ± 35.44 s). Lesioned rats showed a similar behavior when facing the shortest depth, but had a significantly increased number (23.28 ± 2.35 episodes) and latency (300 ± 0.00 s) of HD compared to normal rats (9.25 ± 1.37 episodes and 185.87 ± 35.44 s) when facing the greatest depth (30 cm). This suggests that HD may be a depth-measuring behavior related to risk assessment.

Pedagoginen strategia korkeakoulutuksessa

Referee-artikkeli

Functional mapping of the cardiorespiratory effects of dorsal and median raphe nuclei in the rat

The dorsal (DRN) and median (MRN) raphe nuclei are important sources of serotonergic innervation to the forebrain, projecting to sites involved in cardiovascular regulation. These nuclei have been mapped using electrical stimulation, which has the limitation of stimulating fibers of passage. The present study maps these areas with chemical stimulation, investigating their influence on cardiorespiratory parameters. Urethane-anesthetized (1.2 g/kg, iv) male Wistar rats (280-300 g) were instrumented for pulsatile and mean blood pressure (MBP), heart rate, renal nerve activity, and respiratory frequency recordings. Microinjections of L-glutamate (0.18 M, 50-100 nl with 1% Pontamine Sky Blue) were performed within the DRN or the MRN with glass micropipettes. At the end of the experiments the sites of microinjection were identified. The majority of sites within the MRN (86.1%) and DRN (85.4%) evoked pressor responses when stimulated (DRN: deltaMBP = +14.7 ± 1.2; MRN: deltaMBP = +13.6 ± 1.3 mmHg). The changes in renal nerve activity and respiratory rate caused by L-glutamate were +45 ± 11 and +42 ± 9% (DRN; P < 0.05%), +40 ± 10 and +29 ± 7% (MRN, P < 0.05), respectively. No significant changes were observed in saline-microinjected animals. This study shows that: a) the blood pressure increases previously observed by electrical stimulation within the raphe are due to activation of local neurons, b) this pressor effect is due to sympathoexcitation because the stimulation increased renal sympathetic activity but did not produce tachycardia, and c) the stimulation of cell bodies in these nuclei also increases the respiratory rate.

Sosiaalisen ilmapiirin yhteys työturvallisuuteen perusopetuksen käsityön opetuksessa

Tutkimuksen tarkoituksena on saada uutta tietoa sosiaalisen ilmapiirin yhteydestä käsityöoppiaineen ja erityisesti sen teknisen työn sisältöalueiden työturvallisuu- teen, jotta käsityön opetusta voidaan kehittää työturvallisuusnäkökulmasta parem- paan suuntaan. Tutkimusongelmanamme onkin, miten perusopetuksen käsityön teknisen työn sisältöalueisten oppituntien aikana vallitseva sosiaalinen ilmapiiri on yhteydessä työturvallisuuteen? Tutkimusongelmaan etsimme ratkaisua haastatte- lemalla viittä käsityön teknisen työn sisältöalueita yläkoulussa opettavaa opettajaa ja havainnoimalla heidän oppituntejaan. Tutkimuksen teoreettisessa viitekehyk- sessä esitellään tutkimuksen aiheen kannalta keskeisimmät käsitteet, joita ovat työturvallisuus, turvallisuuskulttuuri, turvallisuuskasvatus, käsityön oppimisympä- ristöjen turvallisuus, käsityön oppimista koskeva työturvallisuusnormisto, sosiaali- nen ilmapiiri, ryhmädynamiikka, opettajan ja oppilaiden välinen vuorovaikutus sekä ryhmän roolit. Koska tutkimuksemme uusi tieto pohjautuu pääosin opettajien kokemuksiin, hei- dän työuransa aikana tekemään havainnointiin ja tutkijoiden omaan havainnointiin, toteutettiin tutkimus fenomenologisen tutkimusstrategian mukaisesti kvalitatiivisen tutkimuksen keinoin. Aineisto kerättiin teemahaastattelun, sekä osallistumattoman havainnoinnin keinoin. Litteroitu haastatteluaineisto analysoitiin teoriaohjaavalla sisällönanalyysillä, johon havainnointiaineistoa suhteutettiin. Tutkimustuloksista käy ilmi, että selkeä ja suora yhteys sosiaalisen ilmapiirin ja työturvallisuuden välillä jää puuttumaan tai on melko harvinainen. Kaikista tutki- musongelmamme kannalta tärkeistä käsitteistä (ryhmädynamiikka, ryhmän roolit, opettajan ja oppilaiden välinen vuorovaikutus ja sosiaalinen ilmapiiri) löytyi yhteyk- siä ja yhtymäkohtia työturvallisuuteen, mutta aineistosta voimakkaimmin ja luku- määräisesti eniten nousi esille opettajan ja oppilaiden välisen vuorovaikutuksen yhteys työturvallisuuteen. Vuorovaikutustilanteet voivat tutkimustulostemme perus- teella toimia käsityön opetuksessa suoraan työturvallisuutta rakentaen. Vuorovai- kutus ilmenee myös työturvallisuutta ylläpitävässä ja kehittävässä toiminnassa, kuten esimerkiksi opettajan ja oppilaiden välisen luottamuksen rakentamisessa oppilaantuntemuksen kautta, sekä turvallisuuskulttuurin kehittämisessä. Asiasanat: työturvallisuus, sosiaalinen ilmapiiri, turvallisuuskulttuuri, vuorovaikutus, ryhmän roolit, ryhmädynamiikka, käsityön opetus