Faculty of Veterinary Medicine University of Zagreb
Abstract
Electroencephalographic (EEG) studies were conducted during experimental pain induction in goats to find the association between routine managemental stress and EEG patterns. Duplicate EEG records from 4 adult (age 8 - 12 months, 10 ± 2 kg body mass) female goats (crossbred Jamunapari and local), using bipolar scalp electrodes were obtained. Pain was induced in a conscious and locally anaesthetised state using a rubber tourniquet applied at the base of the tail and fastened. Xylocaine 2% was used as an injection in the epidural space to achieve local anaesthesia. EEG recordings were taken at 0, 2 and 5 min. after pain application and at the same time intervals after removal of the tourniquet. The EEG frequencies upon pain induction in conscious and epidural anaesthetized states recorded were 38.50 ± 1.96, 33.88 ± 1.42, 31.25 ± 1.39 and 41.88 ± 0.91, 35.63 ± 0.94, 31.50 ± 0.82 Hz at 0, 2 and 5 min of application of pain stimulus, respectively. The frequencies ranged from 26 to 46 Hz in conscious and 27 to 45 Hz in epidural anaesthetized states, whereas amplitudes were higher after 2 min of pain application in both states. With tourniquet removal, the frequency increased significantly (P<0.05) after 2 min in a conscious state, whereas in an epidural anaesthetized state, it increased initially and then declined significantly (P<0.05). The amplitudes and frequencies during pain induction and removal were found to be significantly (P<0.05) different from each other and significantly (P<0.05) higher than in the control (27.75 ± 1.13 Hz and 5.80 ± 0.21μV). Prominent behavioural changes were observed with pain induction. Hence EEG changes can be used as a tool to understand and quantify painful distress in goat.Provedena su elektroencefalografska (EEG) istraživanja kod pokusno izazvane boli u koza sa svrhom da se ustanovi utjecaj stresa uzrokovanoga proizvodnim procesom na elektroencefalogram. Analizirani su rezultati nakon dvokratnoga postupka EEG-a primjenom bipolarnih elektroda na kožu lubanje u četiri odrasle koze (križane Jamunapari i lokalne) u dobi od 8 do 12 mjeseci, tjelesne mase 10 ± 2 kg. Bol je bila izazvana čvrstim stezanjem gumenoga poveza na bazi repa u koza bez anestezije i u koza s epiduralnom anestezijom. Za regionalnu je anesteziju bio upotrijebljen 2 %-tni ksilokain ubrizgan u epiduralni prostor. EEG je bila provedena 0., 2. i 5. minute nakon izazivanja boli te 0., 2. i 5. minute po prestanku bolnoga podražaja. Frekvencija EEG nakon bolnog podražaja u koza bez anestezije iznosila je 38,50 ± 1,96 Hz 0. minute, 33,88 ± 1,42 Hz 2. minute i 31,25 ± 1,39 Hz 5. minute, a u koza s lokalnom anestezijom 41,88 ± 0,91 Hz, 35,63 ± 0,94 Hz i 31,50 ± 0,82 Hz. Frekvencije su se kretale od 26 do 46 Hz u koza bez anestezije, a 27 do 45 Hz u koza s primijenjenom epiduralnom anestezijom, dok su amplitude bile veće nakon 2 minute bolnog podražaja u obje skupine. Frekvencije su se značajno povećale (P<0,05) dvije minute nakon prestanka bolnog podražaja u koza bez lokalne enestezije, dok su se u onih s epiduralnom anestezijom početno značajno povećale, a zatim značajno smanjile. Amplitude i frekvencije za vrijeme i nakon bolnog podražaja bile su međusobno značajno različite, a također i značajno veće nego u kontrolnih koza (27,75 ± 1,13 Hz and 5,80 ± 0,21 μV). Značajne promjene u ponašanju životinja bile su uočene nakon bolnog podražaja. Promjene u elektrokardiogramu mogu se rabiti za proučavanje boli i određivanje jačine boli u koza
