Iranian Society of Physiology and Pharmacology
Physiology and Pharmacology
24765236
24765244
16
1
2012
4
1
Reconstruction of the neural network model of motor control for virtual C.elegans on the basis of actual organism information
1
10
EN
Zahra
Nasem Ashora
N
Majid
Hassanpour-ezatti
Shahed University
Hassanpour@shahed.ac.ir
Y
Behrooz
Raesi
N
Ardeshir
Dolati
N
Introduction: C. elegans neural network is a good sample for neural networks studies, because its structural details
are completely determined. In this study, the virtual neural network of this worm that was proposed by Suzuki et al. for
control of movement was reconstructed by adding newly discovered synapses for each of these network neurons. These
synapses are newly discovered in the actual organism by laser ablation technique.
Methods: An input weight of each neuron in this network was obtained from wormweb site. Internal state of each
neuron and the whole network in this new situation were calculated after mathematical modeling. Then output of the
network in this new model was simulated and drawn by Simulink software in MATLAB environment and compared
with Suzuki model outputs.
Results: The results show that in spite of adding new synapses to the last model, its output shape does not change
and preserve its sinusoidal form, and only its frequency, phase and amplitude of internal state of whole network are
changed after modification. Also, adding of these new synapses to models change silent neurons in forward motion in
Suzuki model to sinusoidal internal state producing neurons in this new situation.
Conclusion: These findings not only show that this neural network has high capability for production of more
output patterns than previously supposed, but also illustrates the effect of addition of new synapses per each neuron and
rewiring on the whole network outputs as a simulation of situation that possibly happens after neural plasticity.
C. elegans, motor neural network, internal state
http://ppj.phypha.ir/article-1-824-en.html
http://ppj.phypha.ir/article-1-824-en.pdf
Iranian Society of Physiology and Pharmacology
Physiology and Pharmacology
24765236
24765244
16
1
2012
4
1
Alterations of the electroencephalogram sub-bands amplitude during focal seizures in the pilocarpine model of epilepsy
11
20
EN
Sahel
Motaghi
N
Mohammad
Niknazar
N
Mohammad
Sayyah
sayyahm2@pasteur.ac.ir
Y
Vahab
Babapour
N
Bijan
Vosoughi Vahdat
N
Mohammad Bagher
Shamsollahi
N
Introduction: Temporal lobe epilepsy (TLE) is the most common and drug resistant epilepsy in adults. Due to
behavioral, morphologic and electrographic similarities, pilocarpine model of epilepsy best resembles TLE. This study
was aimed at determination of the changes in electroencephalogram (EEG) sub-bands amplitude during focal seizures in
the pilocarpine model of epilepsy. Analysis of these changes might help detection of a pre-seizure state before an
oncoming seizure.
Methods: Rats were treated by scopolamine (1mg/kg, s.c) to prevent cholinergic effects. After 30 min, pilocarpine
(380 mg/kg, i.p) was administered to induce status epilepticus (SE) and 2 hours after SE, diazepam (20 mg/kg, i.p) was
injected to suppress the seizures. EEG was recorded in the epileptic rats by superficial electrodes. EEG signal in each
rat was decomposed to its sub-bands alpha, beta, gamma, theta and delta by Daubechies wavelet transform. The power
(square of amplitude) of sub-band during focal seizures was compared with the same sub-band in pre-ictal stage and the
percent of changes in each rat was calculated.
Results: SE occurred in 65% of the animals and happened 39.4±5.4 min after injection of pilocarpine. Focal and
generalized seizures were developed 3.8±0.4 and 7.0±0.5 days after SE, respectively. Although power of EEG and its
sub-bands decreased during focal seizures, the changes were not statistically significant. The greatest decrease in power
pertained to beta and gamma sub-bands, while alpha and theta sub-bands underwent the least changes.
Conclusion: Based on the protocol used in this study, it seems that the power of EEG sub-bands does not change
during focal seizures in pilocarpine model of epilepsy.
Electroencephalogram, Focal seizures, Pilocarpine
http://ppj.phypha.ir/article-1-802-en.html
http://ppj.phypha.ir/article-1-802-en.pdf
Iranian Society of Physiology and Pharmacology
Physiology and Pharmacology
24765236
24765244
16
1
2012
4
1
Frequency-dependent electrophysiological properties of concealed slow pathway of isolated rabbit atrioventricular node preparation after fast pathway ablation in a functional model
21
32
EN
vahid
khori
Golestan Cardiovascular Research Center, Gorgan, Iran
vaphh99@yahoo.com
N
samaneh
Naeimipour
Department of Biology, Faculty of Basic Science, Azad University Science & Research Center, Tehran
N
Ali-Mohammad
alizadeh
Cancer Research Center, Tehran University of Medical Sciences, Tehran, Iran
N
mona
pourabouk
Golestan Cardiovascular Research Center
abook_8181@yahoo.com
N
fakhri
Badaghabadi
Golestan Cardiovascular Research Center
nazari_2005@yahoo.com
N
maryah
Rajaei
Golestan Cardiovascular Research Center
N
sepideh
Shariatnezhad
Golestan Cardiovascular Research Center
N
hamidreza
Moheimani
Golestan Cardiovascular Research Center
N
saeed
saleki
Golestan Cardiovascular Research Center
N
mohammadali
Zeyghami
Golestan Cardiovascular Research Center
N
mohsen
Nayebpour
Department of Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
vaph99@yahoo.com
Y
Introduction: Intranodal pathways of atrioventricular (AV) node play a vital role in the delay of conduction time in
response to various atrial inputs. The present study was aimed to determine the frequency-dependent
electrophysiological properties of concealed slow pathway according to a functional model of isolated rabbit
atrioventricular node preparation after fast pathway ablation.
Methods: Experiments were carried out in rabbit isolated heart AV-nodal preparations (N=8) by
superfused/perfused mode. Extracellular recording was carried out from transitional cells of posterior and anterior
extension of AV-node and upper part of atrium and its bundle. Unipolar silver electrode (100 μm) and direct voltage
(100-110 V) was applied to create AV-nodal fast pathway ablation.
Results: Minimum conduction time (AHmin) was significantly increased after fast pathway ablation (p<0.05). Fast
pathway ablation had no significant impact on fatigue phenomenon but significantly reduced facilitation value (p<0.05).
Rate-dependency properties of concealed slow pathway were explained according to functional nodal model.
Conclusion: The mathematical functional model accurately simulated frequency-dependent electrophysiological
properties of concealed slow pathway after fast pathway ablation, but some modifications are necessary for accurate
prediction of nodal behavior in various cycle lengths and in arrhythmia. Concealed slow pathway may be considered as
a potential electrophysiological substrate of fatigue and facilitation phenomenon
Mathematical analysis, concealed slow pathway, fast pathway, ablation atrioventricular node
http://ppj.phypha.ir/article-1-792-en.html
http://ppj.phypha.ir/article-1-792-en.pdf
Iranian Society of Physiology and Pharmacology
Physiology and Pharmacology
24765236
24765244
16
1
2012
4
1
Electrophysiological study of amygdale-induced changes in the excitability of CA1 hippocampal pyramidal neurons in male adult rats
33
43
EN
Zohre
Ghotbeddin
N
Javad
Mirnajafi-Zadeh
N
Saeed
Semnanian
N
Mahyar
Janahmadi
Neuroscience Research Center and Department of Physiology, Medical School, Shahid Beheshti University of Medical Sciences.
mjanahmadi@yahoo.com
Y
Introduction: Many studies have shown that amygdala kindling produces synaptic potentiation by induction of
changes in the neuronal electrophysiological properties and inward currents both in epileptic focus and in the areas
which are in connection with the epileptic focus and have important role in seizure development and progression such
as hippocampal CA1 region. However, cellular mechanisms of these processes are not clear. In the present study,
changes in the electrophysiological properties of hippocampal CA1 pyramidal neurons following amygdala kindling
were examined in rat.
Methods: Animals were rapidly kindled by stimulation of right amygdala (12 stimulation per day, 1 ms pulse
duration at 50Hz). Twenty-four hours after amygdala kindling, electrophysiological properties and inward currents of
CA1 pyramidal neurons were assessed by using whole-cell patch clamp technique.
Results: Amygdala kindling findings show that percentage broadening of the last spike compared to the first spike
during a trains of action potentials was significantly increased in kindled rats (p<0.05). The number of rebound action
potential was significantly increased from 1±1 in control rats to 6±1 in kindled rats (p<0.01). The amplitude of post
stimulus afterhyperpolarization potential (Post AHP) following a trains of action potential was also significantly
(p<0.05) increased in kindled group (-5±2mV) compared to normal rats (-3±1mV). Under voltage clamp condition,
amygdala kindling produced a significantly larger inward current (-5344.25±33.19 pA, p<0.001) in CA1 pyramidal
neurons compared to normal cells (-9203.6±44.99pA).
Conclusion: The present findings show that amygdala kindling resulted in neuronal hyperexcitability through
alteration of the electrophysiological characteristics possibly by increasing the inward currents in hippocampal CA1
pyramidal neurons.
Amygdala kindling, Seizure, Hippocampal Pyramidal Neurons, Whole Cell Patch Clamp Recoding, Inward current
http://ppj.phypha.ir/article-1-801-en.html
http://ppj.phypha.ir/article-1-801-en.pdf
Iranian Society of Physiology and Pharmacology
Physiology and Pharmacology
24765236
24765244
16
1
2012
4
1
Effect of losartan on NOX2 transcription following acute myocardial ischemia-reperfusion
44
53
EN
Fatemeh
Safari
N
Sohrab
Hajiadeh
fa.cardio@gmail.com
Y
Seyed Hosein
Moshtaghion
sa_physio@yahoo.com
N
Mehdi
Forouzandeh Moghadam
N
Shahnaz
Shekarforoush
N
Gholamreza
Bayat
N
Roham
Mazlum
N
Leila
Sattarian
N
Introduction: Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-2 (Nox2) is one of the predominant
sources of ROS production during myocardial ischemia-reperfusion and can be induced by angiotensin II. The evidence
suggests that pharmacological blockers of renin-angiotensin system can exert direct tissue effects independent of their
ability to regulate blood pressure. The mechanism(s) responsible for such direct effects are not well understood. The
aim of this study was to investigate the early changes of cardiac NOX2 gene transcription after myocardial ischemiareperfusion
in rats treated with losartan, an angiotensin type 1 (AT1) receptor blocker.
Methods: Wistar rats were divided into five groups: Control, sham operated, ischemia-reperfusion (group IR),
losartan without ischemia and losartan with ischemia-reperfusion. The animals underwent 30 min of left anterior
descending artery occlusion and subsequent reperfusion for 180 min. The mRNA expression was determined by real
time-PCR in ischemic area of the left ventricle (LV) and non ischemic area of right ventricle (RV).
Results: Compared to control hearts, exposure to myocardial ischemia-reperfusion produced a significant increase
in NOX2 mRNA level in ischemic area of LV (P<0.001) but not in non ischemic area of right ventricle. Although in
losartan group, NOX2 mRNA levels neither in LV nor RV were significantly altered, while in losartan and ischemiareperfusion
group NOX2 mRNA upregulation in ischemic area was significantly suppressed (P<0.01).
Conclusion: Based on the obtained results, it could be concluded that following acute myocardial ischemia–
reperfusion, NOX2 mRNA levels were increased in ischemic area of left ventricle but not in non ischemic area of right
ventricle, suggesting the local effect of ischemia on the gene expression. Furthermore, inhibition of NOX2 transcription
in ischemic area may be a mechanism of the anti ischemia effects of losartan.
Myocardial ischemia reperfusion, losartan, NOX2 mRNA
http://ppj.phypha.ir/article-1-803-en.html
http://ppj.phypha.ir/article-1-803-en.pdf
Iranian Society of Physiology and Pharmacology
Physiology and Pharmacology
24765236
24765244
16
1
2012
4
1
Evaluation of UCP2 expression in the phenomenon of ischemic resistance induced by alternating normobaric hyperoxia in a rat model of stroke
54
61
EN
Firoozeh
Alavian
Tarbiat Modares University
firoozeh_a_a@yahoo.com
N
Sohrab
Hajizadeh
Tarbiat Modares University
Hajizads@modares.ac.ir
Y
Mohammad Reza
Bigdeli
Shahid Beheshti University
bigdelimohammadreza@yahoo.com
N
Gholam Reza
Bayat
Tarbiat Modares University
gbayat2005@yahoo.com
N
Mohammad
Javan
Tarbiat Modares University
mjavan@modares.ac.ir
N
Introduction: ischemic preconditioning is one of the most important mechanisms, responsible for the increased
brain resistance after stroke. One of the most important candidates to ischemia preconditioning is intermittent
normobaric hyperoxia. In this study, the effect of intermittent normobaric hyperoxia on the expression of UCP2 was
investigated in a stroke model.
Methods: Rats were divided into 4 groups (normoxia – sham, hyperoxia – sham, normoxia – stroke and hyperoxia –
stroke). Hyperoxia groups were exposed to 95% inspired O2, for 4 h/day and 6 consecutive days. Oxygen level in the
control groups was %21 (normoxia). After 24 h, stroke groups were subjected to 60 min of right middle cerebral artery
occlusion. After 24 h reperfusion neurological deficit scores were assessed. The brain UCP2 levels were analyzed by
western blot.
Results: The results of this study showed that following brain ischemia-reperfusion, UCP2 levels significantly
increased in the stroke groups compared with the sham group while there was no significant difference in hyperoxia
groups compared with normoxia. Also hyperoxia decreased neurological deficit scores.
Conclusion: Following ischemia, oxidative stress caused by increase of ROS, leads to increased UCP2 levels in
stroke groups. In this study, the neuroprotective effect of hyperoxia is independent of UCP2 expression.
Hyperoxia, Stroke, Preconditioning, UCP2
http://ppj.phypha.ir/article-1-768-en.html
http://ppj.phypha.ir/article-1-768-en.pdf
Iranian Society of Physiology and Pharmacology
Physiology and Pharmacology
24765236
24765244
16
1
2012
4
1
Effect of Vitex agnus-castus fruits hydroalcoholic extract on sex hormones in rat with induced polycystic ovary syndrome (PCOS)
62
69
EN
Gholamali
Jelodar
shiraz University
jelodar@shirazu.ac.ir
Y
Kobra
Askari
Payam Noor University
askarib81@yahoo.com
N
Introduction: PCOS is an important reproductive and endocrine disorder in women in the reproductive age. Present
reports indicate that Vitex agnus-castus acts through hypothalamus-pituitary axis. This study was carried out to evaluate
the effects of Vitex fruit hydroalcoholic extract on the alteration of sex hormones in a PCOS animal model.
Methods: Following 14 days of monitoring of estrous cycles of rats, 32 animals with regular cycles were selected
and randomly divided into four groups as follows: Control, treatment-control or sham (received 365 mg/kg Vitex extract
for 30 days), PCO (received letrozole 1mg/kg for 28 days to induce PCOS) and PCT (treated with Vitex extract 365
mg/kg for 30 days after induction of PCOS). On the last day of experiments, estrous cycles of all animals were detected
and blood was collected by heart puncture for evaluation of hormone levels.
Results: The results showed that serum estradiol and progesterone levels decreased, while testosterone and DHEA
levels increased following induction of PCO. No significant changes were observed in the hormone levels of the sham
group compared to control. In the group treated with Vitex extract, a significant increase in serum levels of progesterone
and a significant decrease in the serum testosterone levels were observed, however serum levels of estrogen and DHEA
did not change significantly.
Conclusion: Vitex agnus-castus fruit extract can improve serum levels of testosterone and progesterone in an animal
model of PCOS, however it cannot change estrogen and DHEA levels significantly.
Polycystic ovary syndrome, Vitex agnus-castus, Rat, Sex hormones
http://ppj.phypha.ir/article-1-816-en.html
http://ppj.phypha.ir/article-1-816-en.pdf
Iranian Society of Physiology and Pharmacology
Physiology and Pharmacology
24765236
24765244
16
1
2012
4
1
Effect of ICV injection of ghrelin and leptin on T3 and T4 plasma levels in Rat
70
78
EN
Ommolbanin
Amoo-Rajabi
rbani1359@gmail.com
Y
Ali
Moghimi
moghimi@um.ac.ir
N
Homayoon
Khazali
Hkhazali@hotmail.com
N
Introduction: Ghrelin, increases food intake, decreases T3 and T4 concentrations and stimulates insulin release,
while leptin reduces food intake and suppresses appetite. Considering the importance of thyroid hormones, ghrelin and
leptin in body metabolism, the purpose of this study was to investigate the effect of interactions between ghrelin and
leptin (injected via ICV route) and plasma T3 and T4 concentrations in rats.
Methods: Fifty-six Wistar male rats (230 to 250 g/BW) were randomly divided into 7 groups. Groups 1, 2 and 3
received 1, 3 and 5 nmol ghrelin, while groups 4, 5 and 6 received 1, 5, 10 nmol leptin (2 μl via lateral cerebral
ventricle). Animals in the 7th group received 5 nmol ghrelin with 10 nmol leptin via the same route for 3 days. Blood
samples were collected daily starting from one day before until one day after infusions and plasma samples were used to
assess T3 and T4 concentrations by RIA. To ensure proper cannulation, perfusion and brain slices were performed.
Results: The results indicated that ghrelin significantly decreased T3 and T4 concentrations, whereas leptin increased
these concentrations. The simultaneous injection of ghrelin and leptin significantly reduced the inhibitory effect of
ghrelin on thyroid hormones concentrations.
Conclusion: According to the results and other researchers’ suggestions, the opposite effects of leptin and ghrelin
could be emphasized and some hormonal mechanisms for these 2 hormones (transmitters) such as HPA and/or HPT
axes or MSH systems could be suggested.
Ghrelin, leptin, T3, T4, ICV injection
http://ppj.phypha.ir/article-1-764-en.html
http://ppj.phypha.ir/article-1-764-en.pdf
Iranian Society of Physiology and Pharmacology
Physiology and Pharmacology
24765236
24765244
16
1
2012
4
1
Alterations in dopamine related behavior of the offspring of pregnant Wistar rats exposed to noise pollution stress
79
85
EN
Tayebeh
Hassanvand
N
Mohammad
Balooch
N
Mahnaz
Azarnia
N
Homeira
Zardooz
N
Marjan
Erfani
N
Seyedeh Yassaman
Hosseini
h.sahraei@bmsu.ac.ir
Y
Hedayat
Sahraei
N
Introduction: Effects of stress on nervous system activity and development are well defined. In the present study,
the effects of maternal stress on dopamine-related behavior in the offspring were studied.
Methods: Female pregnant Wistar rats (200 g) were randomly exposed to the noise pollution stress (125 db) for 14
days (5 min/day). The time of exposure was random in order to avoid adaptation. The offspring were nursed by their
mothers until the adolescence (200 g-3 mounts of age). These animals were examined for their seeking behavior
including rearing, sniffing and locomotion using open field method. Twenty four hours later, they received
subcutaneous administration of the dopamine D2 receptor antagonist, sulpiride (5 mg/kg) for evaluation of dopamine
receptor sensitization.
Results: Our results showed that sniffing was reduced (P<0.01), but both rearing (P<0.05) and locomotion
(statically non significant) activity in the F2 of stress group was increased. Injection of sulpiride reduced animals
activity (sniffing, rearing and locomotion) in both groups but the reduction was more pronounced in the stress group
(P<0.001).
Conclusion: It could be concluded that dopamine-related behavior differed in the experimental group, which was
exposed to stress during intra-uterine life. In addition, the experimental group showed a pronounced response to
sulpiride, which may be due to alteration in brain dopamine system activity in these animals.
Noise Pollution Stress, D2 Dopamine Receptors, Sniffing, Rearing, Locomotion
http://ppj.phypha.ir/article-1-805-en.html
http://ppj.phypha.ir/article-1-805-en.pdf
Iranian Society of Physiology and Pharmacology
Physiology and Pharmacology
24765236
24765244
16
1
2012
4
1
Effect of repeated morphine and tramadol administration on the motor behavior in the neonatal period
86
94
EN
Morteza
Gholami
biologygholami@gmail.com
Y
Samad
Zare
s.zare@urmia.ac.ir
N
Introduction: Motor behavior and coordination impairment are known side effects of opioid treatment, yet very few
studies have investigated the effects of tramadol on motor behavior, or compared its effect with the effect of an opioid.
This study investigates the effects of chronic injection of morphine and tramadol on rat motor function during infancy.
Methods: Neonate rats (n=56) were randomly divided into three groups. On postnatal days 8-14, one group received
saline and two other groups received tramadol and morphine with a dose-dependent manner. On postnatal day 21, each
group was divided into subgroups, which received morphine, tramadol or saline again on postnatal days 22-26. Finally,
on postnatal days of 22 and 26, the motor behavior was studied.
Results: On postnatal day 23, tramadol caused an increase the falling rate from Rotarod (P<0.001), But there was
not any significant difference between morphine groups. On postnatal day 26 rat, there was a significant difference only
for morphine groups that received additive doses.
Conclusion: The last dose of morphine (15 mg/kg) interferes with motor behavior of immature rats, whereas
tramadol with additive doses on the first two days (3-6 mg/kg) caused an impairment in motor behavior of immature
rats, but could not maintain this ability for the rest of the days of the injection (until 26 day).
tramadol, rotarod, morphine, neonatal period
http://ppj.phypha.ir/article-1-790-en.html
http://ppj.phypha.ir/article-1-790-en.pdf